We scored some free passes to ANA Sports in Forest Hills/Cascade and decided to use them for the preschool (up to age 6) open gym they hold on Fridays from 10-11 am.  The cost for nonmembers is $6 per child.

We had an awesome time. There is a rope swing, tons of balance beams, a long trampoline, an in ground trampoline for the little ones, and lots of foam pits to climb, jump, and play in.  I had to stay pretty close to my 23 month old, but my 5 year old didn't need much help from me during the  hour we were there.