They had access to wood and tools. We closely supervised.
They both made an airplane with very different designs
This climbing structure is HUGE. We knew we would want to go up it.
Going up requires hair nets and helmets. This was an exceptionally good idea as we all bumped our heads much more than expected as we climbed, crawled, and twisted our way through.
Here is another picture of the climber. It is too big to get in any one photo. All of those vertical boards are part of it. You can see it starts near the bottom left of the photo and goes up more than three stories.