This one heck of a structure that our two granddaughters, 2 and 3 years old,  can not stay of off. It is a sound structure though the instructions can be a little confusing at times.  If I was to change one item it would be that all the pieces that good together are in the front part of the instructions. Also look at every page and sort the hardware and place in a container for easy use. this ensure all hardware is there.