I have 3 kids too (11, 5 and 2 - all boys)...the age difference can make it a tad challenging to find something that all of them will enjoy. We all had a great time at Emma Prusch Farm Park in San Jose. There were tractors and stuff for the boys to climb on, there is a farm area with animals, stables, a huge lawn area to run and play on, plenty of shade trees, clean bathrooms, a orchard and veggie garden you can walk through and a really nice and big play area, the play structure is covered with a type of mesh which is great on hot days and to keep down any sunburns. We really enjoyed it. Oh, and it's free! :)
Address: 647 South King Rd San Jose, CA 95116
Tel: 1 ###-###-####