Although it can easily claim to have Key West [1]’s best beach, Fort Zachary Taylor State Park (300 Truman Ave., 8 a.m.–sunset daily, $3.50) doesn’t really have a whole lot of competition. Nonetheless, the beach, though small, is quite pleasant. There are excellent snorkeling opportunities off the beach, where schools of parrot fish, snapper, and other fish can frequently be spotted among the coral reefs.
Visitors can also enjoy fishing on the west side of the park, as well as biking and hiking along some pleasant short nature trails. The fort itself isn’t much to see, as it seems to be in a permanent state of rehabilitation; still, park rangers offer daily guided tours on which you can poke around in the few open areas of the fort and see Civil War–era cannons and other military artifacts.
Links:
[1] http://www.moon.com/destinations/florida/florida-keys/key-west