(Photo: Aerial View of Alcatraz via Shutterstock)Alcatraz Island, San Francisco Bay
More than "just" the site of America's most infamous former federal penitentiary, Alcatraz Island is also worth the trip for its natural side—including tide pools, gardens, and bird colonies. Ferries arrive every half hour, allowing you to customize your visit to see whatever you'd like on your own schedule. And did we mention those bay views? It's almost enough to make us jealous of the former inmates. (But we prefer the flexibility to leave at the end of the day.)
