Ranking high up on the list of parks with cool play areas around town is Alameda Park, located at the corner of Garden Street and E. Micheltorena Street in Santa Barbara. Alameda Park has an 8,000 sq ft mostly wooden play structure that was built by local residents. This is the most unique play structure of any park I'm aware of in Ventura and Santa Barbara Counties (though the newer play structure at Gates Canyon Park in Calabasas gives it a run for its money).
Your kids will fall in love with the nooks, crannies, steps, bridges and places to hide in this play structure. There are also swings and things to climb on. The park itself is 2 blocks long and one of the oldest parks in Santa Barbara. It is next door to the beautiful Alice Keck Park Memorial Garden. Plenty of grass, spectacular, large shade trees and much more make this a perfect picnic lunch stop when you're in town.
More information at www.santabarbaraca.gov/gov/depts/parksrec/parks/features/horticulture/alameda.asp.