When we go to San Diego, one of our favorite places to go for a day hike is the Torrey Pines State Nature Reserve. It's a beach cliff area just below the famous golf course and UC San Diego. This day we went there was a sinkhole due to recent rains, so we had to park at the bottom and walk up the hill, but typically you can drive up and hike out to various points with views of the ocean and down towards the beach.