Adventure Playground on Mercer Island


At Deane Children’s Park on Mercer Island (part of Island Crest Park – 5801 Island Crest Way) there’s an Adventure playground, where children are given hammers and nails, and encouraged to go build, play, explore, and discover. Here’s how Red Tricycle describes it:

an ever-changing carpentry wonderland that’s completely kid-built, poised to capture the imagination… What’s been created so far will surely inspire your lil’ builder to add her own touches or modify a current design. In fact, the organic, continually-evolving nature of this park is part of its cool-appeal. Each day the park is open, new structures pop up simply by adding, removing or connecting to the existing forts, bridges, ladders, ramps and swings.

This is a land where children build their own playground! They build tree forts, add makeshift slides and swings, and add in fun imaginative details like mailboxes and chairs. When they tire of building, they explore other structures, climbing up high on rickety bridges, ducking low into hideouts, and clambering across the hillside. It’s very fun!!!

There are lots of things I LOVE about the Adventure Playground, which I’ll share below. But, there are some definite safety risks there, and it’s not for a parent who is faint of heart. And it’s NOT appropriate for kids under 4. Be sure to read the cautions below.

When to Go

This Tuesday and Wednesday (Aug 30 & 31), they’re open 1 – 4 pm. Then they’re open on Sundays 9/11, 9/18, and 9/25 from 1 – 4 pm. Admission is free, but please donate! (JayMarc Homes is sponsoring the playground this year, but support from participants is important to showing Mercer Island parks that we appreciate this opportunity!) It can be closed for inclement weather.

What to Expect

It’s ESSENTIAL to wear good, solid, closed toe shoes with sturdy soles!! There are nails and other hazards everywhere you step. It would be best to wear long pants, probably – we were there on a high 80’s day but it’s very wooded, so it doesn’t get very hot. Bringing a water bottle would also be a good idea and many parents bring snacks.

When you arrive, the parent must sign a waiver. You’re given a copy of the rules: basically keep track of your tools, respect others, do not take down existing structures, be safe, and report injuries or emergencies. Kids 12 and under must be accompanied by an adult.

Then they check out a toolbox to your child. It contains items like a kid size hammer, a screwdriver, a level, safety glasses, nails, screws, a big pencil. and a measuring tape. Some might have a saw. You can also pick up a construction helmet. Wood scraps are scattered everywhere on the ground – you scavenge around for what you need. Occasionally there are specialty items: deck railings, bed frames, playground slides. When I went in 2015, I wished there were rope, because it really increases the building possibilities.  In 2016, we found some ropes we were able to use to make a swing.

In the future, I plan to bring an adult size hammer – sometimes we needed more leverage to pound or pull a nail than you can get with a kid size hammer. We could have also used a pocket knife to cut a rope with.


What you’ll Find

The playground opened July 5th, so at this point in the season, you’ll find lots of established structures that have been built by the kids who came before you. The photos below are from 2015 and 2016. Click on any photo for a larger view.

Some of the existing structures are quite impressive: solid, stable, serious pieces of construction:

stable1 stable2 stable3

Some are a little more rickety and haphazard.

rickety4 rickety3 rickety2 rickety1

Some kids have added warning signs, some label their creations, and some create whimsical details:

sign2 sign1

My son loves running around and exploring what’s there – just like any playground he goes to, the first things he wants to do are: climb ladders, run up ramps, slide down slides, get as high up as he can, and swing on the swing. He was having a fabulous time just playing and exploring till we got to the swing… The existing swing he found was really a disappointment – it didn’t hang straight, and didn’t swing well. So, it was time to start building! We worked together to build a swing. (See a video of the swing here.)

ramp slide high swing installation

The Inspiration

The playground is inspired by free play advocates, and advocates for the benefits of risk-taking for kids and the benefits of allowing kids to tinker and build real things with their hands and real tools. There are several adventure playgrounds in England and Europe and the trend is moving to America. Learn more about the movement here:

What Kids Learn

There is so much to be learned in this environment!!

  • Creativity. As a child plays and explores what is already there, they learn about the range of possibilities, and start creating their own vision of what they would like to see in this world, and then set about making that vision a reality.
  • Construction skills. Kids learn about hammers, nails, saws. They learn about measuring, rope tying, adding in shims to stabilize something. So many skills that they discover the need for in the moment of building.
  • Safety assessment. They learn to test their work to see if it’s stable and safe, and re-build as needed.
  • Failure and trying again in a new way. Not everything they attempt works! I was watching a mom and daughter try to fit a bed railing in between two existing uprights. It kept tipping backwards, so they added support boards behind it. But then it was tipping forwards, so they added more boards, and it still tipped, so they had to figure out how to build a better stabilizer to hold it in place.
  • Teamwork. When installing an 8 foot long plank on a 4 foot tall platform, you need help. You can’t do it alone. So, you ask for help, you explain what you’re trying to do. You work together with someone. If they have different ideas, you might need to learn some conflict resolution skills.
  • Satisfaction in a job well done. The kids had just even more fun playing here than they would in any regular playground, but beyond that, they had a whole other layer of pride, sense of competence, and boosted confidence. They all left the playground bragging about what they had created together.

Read more about what kids learn here, where I share more photos, and stories from our trip.

Safety Issues

There are definite safety issues. Many of the ramps are shaky, there are lots of high platforms without rails, and narrow wobbly bridges several feet in the air. There’s lots of potential for falls. Also, the kids are working with hammers, nails, and saws. Some have clearly gotten safety coaching. Others have clearly not.


When I was there in 2015, if my memory is correct, most of the wood was stacked up in a wood pile near the front gate. This year, the wood was randomly scattered EVERYWHERE across the site. This made it much easier to build… when you had an inspiration, you just searched the ground nearby and you’d find a board you needed, or a branch or a rope. But this means you better pay close attention when you walk! And if you fell, you’d be as likely to land on a board as on the soft ground of the woods. And most boards on the ground have nails sticking up out of them. (Remember those sturdy shoes!)

boards2 boards1 nails2

There were also LOTS of loose nails on the ground. This is what I picked up just from under the platform where we built our handrail and swing.


Another issue is that there’s LOTS of places where kids pounded a 3 – 4 inch nail through a 1 – 2 inch thick board, and that means there’s a section of nail sticking out on the other side… so watch out for protruding nails on the backs of ladders and on the bottoms of platforms.

I believe kids can stay safe there, but only if you emphasize to your child the importance of caution. An article in Seattle’s Child says that there have been few injuries, and most of those have been adults, because the kids are being more cautious.

I certainly taught my child how to be careful there!  I let him explore, but I made sure he knew to watch the ground when he walked (no running), test to be sure something is stable before going on it, check to be sure there’s no nails poking out before you put your hand there, and so on.

I LOVE the free play aspect of this playground, but I also think that with great freedom should come great responsibility. I wish that all parents would give their kids some basic education on the way in, not just about how to move safely through the playground and how to use tools safely, but how to be responsible for keeping it safe for others. I wish they were taught to be sure their structures were as stable as possible before walking away and leaving them for other kids to play on. I wish kids were encouraged to stack all their scrap wood in tidy piles, near worksites, but not directly in the range or where someone could fall. I wish they were encouraged to pick up any nails they drop, and to also scan their worksite for any hazards before leaving for the day. I wish that when kids or parents noticed nails sticking out on the back of a handrail, they take out their hammer and quickly pound it down to keep others safe.

I’m definitely a product of a girl scout / boy scout childhood, and have firmly engrained the idea of “leave the site cleaner than you found it.” I feel the users of the playground could use that message, though maybe here it’s “leave the playground safer than you found it.”

Age Guidelines

I personally would not take any child under the age of four here. I think it would be hard to keep them safe. If you have a little one, it’s much better to stick to the traditional safety-tested playground and Deane park has four fabulous play areas not counting the adventure playground! (Read my full review here.)

I took my son last year when he was four. (And I should note, we spend LOTS of time at playgrounds and hiking outdoors and climbing rocks and climbing trees, so he has a lot of physical skills and learned caution from those environments.) I kept a very close eye on him the whole time as he played, and actively educated him about how to stay safe and we didn’t attempt to build anything because I didn’t want to get distracted. We did carry a hammer around with us, and did pound in some loose nails we found.

This year, he’s five, and my husband came too, so we had two sets of eyes to make sure he was safe. So, this year we were able to balance building and supervising him. But I didn’t really have any “sit down and relax” time.

We observed other parents and grandparents with a range of ages, and definitely the 6 – 9 year olds had an adult working closely with them. For the 10-12 year olds, a few parents would sit on a log and read while keeping a vague eye on the kids and calling out suggestions. There weren’t any kids there alone that I noticed, but 12 and ups are allowed to be there without an adult.

If you’d like a building adventure, check it out soon! They’ll dismantle this year’s constructions on September 25th.


Inventors of Tomorrow is moving

I have been running a blog series called Inventors of Tomorrow. Each post includes a full array of activities for a 2 hour STE(A)M enrichment class for children age 3 – 6. I am moving all those posts over to a separate blog:

You will still find posts on STEM topics and outdoor education on this blog: just click on “STEM activities” or “nature activities” on the right hand side bar. (On a mobile device, scroll to the bottom of the page.)


Catapults are a huge hit with kids… being able to launch things into the air and across the room is always exciting!

There are LOTS of ideas online for how to build catapults. I want to present a simple series of catapults that show the evolution of an idea.

Supplies needed: pencil, popsicle / craft sticks, rubber bands, a plastic spoon, an object to launch (e.g. pompom or mini marshmallow or coins)

Stage 1

First, take a popsicle stick (the bar of your lever), balance it over a pencil (your fulcrum). Put an object (your load) onto the end that’s laying on the table. Hit the high end of the stick, the object launches. This is an easy depiction of the simple machine concept of levers (learn more about Levers here.)


Kids will have plenty of fun with this. Launching things is fun. But, they’ll soon discover that this is a weak catapult – we can get a lot better launch by evolving it.

Stage 2

Now, take two popsicle sticks: Use a rubber band to fasten them together at one end. Then slide a pencil (or three craft sticks bundled together) between the sticks until it pushes up against the rubber band. Set it down. Put your pompon (or coin) on the raised end, then use your finger to press down and release. The pom pom will fly much higher!


Stage 3

After they’ve had a good time with this one, you can take this simple design to the next level by creating a spoon catapult. You’ve already got your two popsicle sticks banded together. Use a rubber band to attach a plastic spoon on one (Here’s a picture from to show you where to fasten it.) Slide your pencil in between the sticks, as before (or use two or three popsicle sticks rubber-banded together). Now launch items from the spoon – your launch arm is longer, and you added the springiness of the spoon – does this increase the strength of the launch (i.e. does your object travel farther?)


Stage 4

Now bundle together 5 craft sticks to use as your fulcrum – this is what is shown in the picture above, and you can also find directions at

Is the catapult stronger with a taller fulcrum and more pressure on the rubber bands that bind the launch sticks together? What if you use 8 sticks in your bundled fulcrum?

Stage 5

Use longer bars to build the catapult than popsicle sticks. Maybe rulers? Rubber band them together at one end, and keep using your bundle of craft sticks as a fulcrum.

Continue to experiment… Here’s a very similar catapult built from a couple of wooden yardsticks, a piece of cork (used as fulcrum to separate the two sticks – you could use your stack of popsicle sticks) and some tape (could use rubber bands).


Testing and Talking

As you build a variety of catapults, test them. You can compare on two criteria: which launch the object the farthest and which launch it the most accurately (i.e. can you hit a target with it.)

For more STEM related activities, click on the word STEM in the right sidebar…

Book Series about Simple Machines


[An updated version of this post can be found at:]

There are several series of books about Simple Machines. I got samples from each series, and will write up here my first impressions of each. These are not meant to be in-depth reviews, just snapshots of my opinions. Of course, what book is best depends on your audience and your setting. I am looking for books to read aloud in group time to children age 2.5 to 7. Many of these books that I don’t rate high might be great for a 5 – 7 year old, but I’m trying to find something to appeal to a very wide range.

In this post, I summarize my impressions of the series, based on the books I read (starred). In the attached spreadsheet, I share my specific ratings for the books I read. Here are the four criteria I ranked them on:

  • Pictures: Are they good photos (current, focused, visually appealing) of things that are interesting to kids?
  • Words: Would this be a good read-aloud book for a group of 3 – 6 year olds? Easy to understand and interesting to listen to?
  • Big Idea: Does it get, and adequately convey the key concepts about this simple machine and how it works? (For my summary of what I think those key concepts are, see my Inventors of Tomorrow posts on each of the types of Simple Machines.)
  • Examples: Are there several good examples of the machine that would be interesting to children? (But I don’t want examples of every single way this simple machine can be applied, because sometimes that makes it hard for a young child to remember the big picture.)

Series Name: Amazing Science: Simple Machines. Author: Dahl
Books: Roll, Slope, and Slide*; Scoop, Seesaw, and Raise*; Pull, Lift, and Lower*; Cut, Chop, and Stop; Tires, Spokes, and Sprockets
Review: Engaging pictures and words, though a little high level for us. But I didn’t think the pulley book and inclined plane book did the best job of explaining key concepts.

Series Name: Blastoff Readers: Simple Machines. Author: Manolis
Books: Ramps*; Levers; Pulleys*; Screws; Wedges; Wheels and Axles*
Review: These would be my top choice if I had only 5 – 7 year olds, but they’re a little too long and too sophisticated for my little ones. Brightly colored and engaging pictures. Good diagrams and descriptions of key concepts – very clear. Nice examples

Series Name: Early Reader Science: Simple Machines. Author: Dahl
Books: Ramps and Wedges; Levers; Pulleys; Wheels and Axles*
Review: Pictures OK, but not especially appealing to young ones. Length-wise, it would be OK for circle, but vocabulary a little high level. It gives examples of so many kinds of wheels and axles (steering wheels, gears, sprockets, cranks, cams, etc.) that the basic concept is lost. Does not mention friction.

Series Name: How Toys Work. Author: Smith
Books: Ramps and Wedges*; Levers*; Pulleys*; Screws, Nuts and Bolts*; Wheels and Axles*
Review: I want to love these books. The pictures are great. The language is age appropriate and engaging. There are lots of good examples, all of which are toys and other things that appeal to young children. In some of the books, the big idea is explained well (Pulleys and Screws) But others seem to miss the big idea. (Ramps and Wedges; Wheels and Axles.) I would use these books to engage the younger students, but also want some of the other series to share with the older readers to better explain concept.

Series Name: My World of Science. Author: Randolph
Books: Inclined Planes in my World*; Levers in My World; Pulleys in my World; Wedges in My World*; Wheels and Axles in my World [there doesn’t appear to be a Screws book]
Review: Pictures are fine; words are appropriate level and the book is a good length for circle time, big idea is explained well, and there are lots of examples, but they all tie together in a clear logical way to the same big idea. It ends with asking “can you think of [wedges] you see around you?” Then offers a picture glossary of key words. This is a reliable, useable, but not exciting series.
Note: this series is bilingual English / Spanish. So Wedges in My World is also Cunas en mi mundo. Each page has the text in English first, then Spanish.

Series Name: Simple Machines. Author: Armentrout
Books: Inclined Planes, Levers*, Pulleys*, Screws*, Wedges*, Wheels*
Review: The language level and the length would be fine for 5 – 7 year olds, but too much for our little ones. They also go beyond what we need with our younger age group (level book addresses first, second and third class levers and compound levers.) Pictures are fine, examples are good, but in some books there are so many examples the big idea is lost.

Series Name: Simple Machines. Author: Bodden
Books: Inclined Planes; Levers, Pulleys*, Screws*, Wedges*, Wheels*
Review: They’re pretty books, but photos may be a little artsy for little kids. Words are a little dry. In general concepts are very clear and easy to understand and examples clearly illustrate the ideas. But, I thought the screw book was unclear and jumbled examples together that it wasn’t clear how they related. We used several of these books in our circle times in class, but tried to balance with How Toys Work, which are brighter and more fun.

Series Name: Simple Machines. Author: Tieck
Books: Inclined Planes*, Levers, Pulleys*, Screws*, Wedges, Wheels and Axles
Review: A little long, a little old, and too dry for our purposes. But, I think these are the best descriptions of the big idea. We didn’t read these in circle, but I did have them on the bookshelf for the older kids to check out.

Series Name: Simple Machines to the Rescue. Author: Thales
Books: Inclined Planes to the Rescue*; Levers ttR, Pulleys ttR, Screws ttR*, Wedges ttR, Wheels and Axles ttR
Review: I see these recommended on other people’s sites, but I’m not a fan. The pictures aren’t great, the language is a little advanced. And I just find that they do the weakest job of explaining simple machines concepts. For example, in the screw book, their first example is a lid on a soda bottle, then a spiral staircase, then Archimedes screw, then an olive oil press, and then it talks about things that are held together by screws. Nowhere in there does it really describe what a screw is and what type of work each of these tools has in common.

Series Name: Useful Machines. Author: Oxlade
Books: Ramps and Wedges; Levers; Pulleys; Screws*; Wheels
Review: Good pictures, engaging and easy to understand for 5 – 7 year olds. I have only read the screw book, but I like it a lot. However, I would not use it as the intro to screws. Once kids had a solid grasp of the basics of screws, it does a nice job of giving examples of all the different applications

If you’re teaching about Simple Machines, be sure to check out my Inventors of Tomorrow series… I give examples of lots of hands-on activities you can use with kids 2.5 – 7 to teach these concepts.

Inventors of Tomorrow

I am beginning a new series, called Inventors of Tomorrow, which will feature science, engineering, and nature-related activities for preschool / early elementary age children. [NOTE: In January 2016, I moved all the Inventors of Tomorrow posts over to a new site:]

I teach a class called Family Inventors’ Lab, which focuses on hands-on learning and exploration of ideas from science, nature, engineering, and art. It is a multi-age class for kids age 2.5 – 7. The focus is on tinkering: making things, testing them, re-building them, and testing again, and learning in the process. We have a new theme each week, but they are clustered into units that last 2 – 6 weeks. The Inventors of Tomorrow series shares the activities we do in class: art, science exploration, imaginary play, and more.

DIY Water Wall

pourWhen I built our ball wall / marble run, my goal was to have a flexible design so the pieces could also be used for water play and for a sensory table. With this week’s nice weather, we were able to test the theory, and it was a great success in terms of fun!

You can see there is some leaking that happens around the joints when two same-dimension connectors or pipes are next to each other (which was fine with my son – he liked that there was water coming out everywhere), but probably 50 – 60% of the volume of the water made it all the way through the maze.

splashThe water works work better when you pour slowly, but my son liked the splash effect he got from pouring quickly.

The end point of our water maze was a plastic cup with two magnets glued on it. Whenever it filled up, we replaced it with the other cup, and poured the captured water back through the maze – we also had a tub full of water nearby.

The best part: when the cup fills up all the way with water, the weight is more than the magnets can support, so it slides to the ground. “Level complete!”

DIY Ball Wall


marble run

The theme for this week’s Inventors’ Lab was gravity, so I made a ball wall (aka marble run). This is like those exhibits you find in most children’s museums where where are pipes and joints mounted on magnets. The children can re-arrange them to make any path they choose, then run a marble through them to test their path. They may find that the ball shoots off-course at some point, and need to re-adjust the pipes for the ball to reach its goal. Just playing with these is a great exercise in tinkering and hands-on engineering. My son can play with these for hours, so we decided to make one for home and for class.

I got my original idea from Frugal Fun for Boys.

This was a really easy project once I got the supplies. About three-quarters of the effort was deciding which supplies to buy in what size (and what strength of magnets), so down below, I’ll include my full list, with affiliate links, and the lessons I learned to hopefully make your life easier if you want to replicate. In class, the kids definitely had fun with it!

Note: This marble run is designed for repeated use by lots of kids. I will also be adapting parts of it as the year goes on for water play and sensory play. There are lots of easier / cheaper ways to build a marble run for short term use at home, so I’ll include links to those at the bottom.


Ball wall

Supply List

On Frugal Fun she used regular size marbles, so I needed to adapt her materials a little. In our class, we have children as young as 2.5, so I wanted to use the bigger shooter marbles instead to make them less swallowable.

The materials I used: oil drip pans, 1 1/4 inch PVC joints (45 and 90 degree elbows), 1 1/4 inch PVC pipe, 1 1/4 inch OD clear polycarbonate tubing, a tube with a curved end – it’s part of a p-trap (you can buy the piece separately but I don’t know what it’s called), ceramic magnets, glue, shooter marbles, miscellaneous funnels 1, 2, 3 And a couple dinosaur party cups to catch the balls at the end of the run.

Technical notes / things I learned in the tinkering process

Pipes and joints: Important lesson – 1 1/4 inch PVC pipes are not 1.25 inches around! I think that’s their inside diameter. Outside diameter is 1.66  inches. These pipes and joints are bigger than you need for shooter marbles, You could go down one size, I think. The marbles run just fine through the clear tubing, which has an outside diameter of 1.25 inches, inner diameter of 1 1/8.

Marbles: I liked these shooter marbles (Note: don’t order these… they are regular small marbles, not shooters, despite the description) I also made marble size balls from Model Magic clay, which seemed like a fine idea in advance. They were pretty, they ran through the tubes just fine, and since they were lighter weight, they didn’t knock the tubes out of line as much. But, there were a couple problems. 1) If you mixed them with the marbles, the marbles were heavy enough that if they fell on top of a model magic ball, they’d squish it out of its nice round shape, and then it would start getting caught in tubes. 2) if you step on the model magic balls, they squish flat, and 3) after this accidental discovery, a certain three year old in the class took great pleasure is stepping on all the balls and squishing them flat. If you squish them once or twice, I can re-roll them into a round ball, but after that, they’re pretty much useless.

Funnels: I ordered the widest mouth funnels I could find, but none of these funnels had a wide enough neck for the shooter marble to go through… I sawed the end off the yellow one so a marble would go through, then I taped it to a pipe because at that time I didn’t have a file to file off the rough edges of the cut.)

Magnets: I wanted some that were strong enough that the pipes wouldn’t slip out of place every time you sent a marble through. But, they couldn’t be too strong, as I wanted it to be possible for a three year old to pull the pipe off the metal pan and move it around. The magnets I ordered (linked above) are perfect. I put one on the back of each 45 degree joint, 2 on the back of most items, and three on the 2′ long segment of PVC.

One issue I hadn’t foreseen is that you can’t just lean the pans up against a wall and let the kids play. The first time they grab hold of a pipe to pull it off the metal pan, the metal pan would fall on their head. I could try to teach them to brace with one hand and pull with the other – but that’s not really gonna happen. So, you have to secure the pan. Lots of Pinterest folks who use drip pans for magnet activities mount them on their wall permanently (putting screws through them into the wall) or semi-permanently by putting wide velcro strips on the wall. Neither was an option for me in my classroom, so I used ratchet straps to tie them to a bookcase. The only problem was then you have straps going across the front of the pan. I’m betting you could also use bungee cords… there’s enough of a rim around the pans that the bungee cord could hook to it. But since bungees come in specific lengths, you’d have to know in advance what length you needed.

Or, for home use, don’t buy a drip pan. You can just use your refrigerator to mount your ball wall… just be sure that the marbles can’t roll under the fridge.

This was a very quick and easy project, except for sawing the PVC pipe and clear tubes into the lengths I wanted. Using a hack saw and files to smooth the rough edges was perfectly do-able, but took 15 – 20 minutes per cut, I would guess. Then I learned about Ratcheting PVC Cutters which make the job SO MUCH EASIER!!!

I have also bought some flexible tubing and some T-joints, and plan to experiment with using these items in a water wall and for sensory table play, with either rice or beans.

Easier ways to do a ball wall, and other ideas

Use toilet paper tubes, paper towel tubes and masking tape like Lemon Lime Adventures and Tinkerlab.

Or those same tubes and magnets, like Growing a Jeweled Rose or Teach Preschool.

Or water bottles and magnets, mounted on the fridge instead of a drip pan.

Build a hand-held marble maze in a shoe box lid with craft sticks.

Here’s a collection of links to good options, both DIY and store-bought.

Resource for STEM activities

If you’re looking for 100’s of ideas for hands-on activities to teach science, engineering, and math, check out my other blog,