Thing to do in San Diego?

Our family took a trip to San Diego last May. My children, 5 and 2.5 (at the time), absolutely loved La Jolla and Children's cove. We didn't swim in the cove area but the seals were out in force and was fascinating. Near that area was a place they could wade in and just have fun. We ended up driving driving from Coronado to La Jolla twice upon their request.