Put out a towel on the sand and watch the surfers! If the tide is low, you can go up the beach to the south or north!
Take a stroll on Sunset Cliffs Blvd. and watch the crashing waves.
Hike among the nation's rarest pine tree on trails overlooking the ocean.
Visit Balboa Park and explore the Science Center, Natural History Museum, and Botanic Building and Gardens (or the zoo!).