Take animal-loving kids to San Diego's renowned zoo (sandiegozoo.org), where they can visit Panda Canyon, get a behind-the-scenes tour or stay for a sleepover. Head to the zoo in October, when children ages 3 to 11 are admitted free in honor of the zoo's founding. If sea creatures are more their thing, treat your kids to a day at SeaWorld (seaworld.com). Marvel at Shamu the whale or venture through the Shark Encounter, a 57-foot acrylic tunnel with a stunning view of a shark habitat.
Catch a San Diego Padres game at Petco Park (sandiego.padres.mlb.com). Kids who sign up for free Junior Padres membership enjoy gobs of benefits, such as discount ticket vouchers and exclusive privileges at Sunday Signings, where the young fans can ask players for their autographs. Kids who want to "do" sports rather than watch sports can head to the beach for a surf lesson. Sign up for private or group lessons, which typically include age-specific instruction and all the equipment necessary to ride the waves.
Combine a trip to the beach with a stop at Belmont Park (belmontpark.com), a throwback of an amusement park complete with miniature golf, midway games and the oceanfront Giant Dipper Roller Coaster. Admission to the park is free. Head north about 30 minutes to Legoland California (legoland.com) to check out rides and Miniland USA, which features 20 million Lego bricks pieced together to make replicas of America's landmarks.
Plan for indoor -- and interactive -- fun at the Reuben H. Fleet Science Center (rhfleet.org). Explore hands-on exhibits such as Block Busters, where kids are challenged to build free-form structures using thousands of wooden planks. Other kid-friendly museums are the San Diego Natural History Museum (sdnhm.org) and the New Children's Museum (thinkplaycreate.org), which features art studio spaces, exhibitions and performances.
