David Mobley
Google
This is a great, almost secret, playground in Irvine. It's really awesome, for young and old alike - though most of the features are oriented more towards kids above the toddler age. The big selling point is free play and construction, with lots of supplies for both. They have sand and sand toys, a water/sand/mud feature with excavation equipment, and giant Legos suitable for building castles and houses big enough to fit people. Of course they also have a traditional playground as well as some other amenities (fusbal, ping pong, and it looked like some books to read). On the whole awesome. And free. Because of all the supplies it has set hours and is gated. But free. Very well kept secret and I (and my kids) love it. Though cleanup after the mud feature can be rough. My kids beg to go here.