March yourself to Naval Base San Diego, explore the facility and try to imagine what being a member of the armed forces is like.
If you love the word "free" as much as most people do, you'll be glad to know this military installation is exactly that. Naval Base San Diego is located in San Diego. To keep your sightseeing schedule full while you're in these parts, also drop by San Diego Zoo, Balboa Park and USS Midway Museum.