The Top 10 Landmarks in the US

Located just over a mile from the San Francisco coast, Alcatraz has housed such well-known US criminals as Al Capone and James "Whitey" Bulger. While the island is known for its eponymous prison, Alcatraz is also home to lush gardens and a variety of birds and small animals. Commented one TripAdvisor reviewer, "Alcatraz is an amazing National Park that everyone should visit at least once. You don't realize how big the island is until you arrive on the boat. The audio tour is very informative and you can wander around all day if you'd like."

Average Summer bookable rates in San Francisco: June: $287, July: $285, August: $298

Reason to book now: Escape From Alcatraz Triathlon starts at Alcatraz Island — June 12, 2016

Top-rated tour: Viator VIP: Early Access to Alcatraz and Exclusive Cable Car Sightseeing Tour — tickets start at $190 per person