Historic District: Many ships dock right at St. Augustine Municipal Marina, which is directly opposite St. Augustine's Old Town. Avenida Menendez, running along the marina, is the gateway to this historic village bounded by Bridge Street to the south, King Street to the north and Cordoval Street to the west (though historic sites can be found to the north and south of these blocks). If it's not too hot, the area is extremely walkable.
If you'd rather ride around town, you have a few options. Consider Ripley's Red Train (buy tickets at 254 San Marco Avenue, 170 San Marco Avenue or 19 San Marco Avenue; 904-829-6545; open daily, 8:30 a.m. to 5 p.m.). This hop-on, hop-off service with more than 20 stops offers three sightseeing tours: a general historic tour, one focused on the city's black history and a ghost train adventure. Old Town Trolley Tours (167 San Marco Avenue; 844-388-6452; open daily except Christmas Day, 9 a.m. to 4:30 p.m.) offers a similar service, or you can hail a horse-drawn carriage at the Bayfront between the Fort and the Bridge of Lions (Country Carriages; 904-826-1982; open Sunday to Thursday, 10 a.m. to 10 p.m., Friday and Saturday, 10 a.m. to 11 p.m.).
Start your day by stopping at Castillo de San Marcos (1 South Castillo Drive; 904-829-6506; open daily, 8:45 a.m. to 5 p.m.). This national monument is more than 315 years old. In fact, it's the oldest masonry fort in the continental United States. Park rangers lead tours daily.
The 15-acre Fountain of Youth Archaeological Park is a bit more touristy, with shows and living history reenactments that depict the native Timucua Indians and Spanish settlers. It's also home to the mythical Fountain of Youth. Drink from its waters, and you'll never grow old -- or so legend has it. (11 Magnolia Avenue; 904-829-3168; open daily, 9 a.m. to 6 p.m.)
For something more highbrow, head to Lightner Museum (75 King Street; 904-824-2874; open daily except Christmas Day, 9 a.m. to 5 p.m.). This collection of Victorian antiques and works of art is housed in the former Alcazar Hotel. In 1888, Henry Flagler commissioned architects Carrere and Hastings to build this hotel, and it's still considered a masterpiece of design.
When you want a break, visit the Whetstone Chocolate Factory (139 King Street; 904-217-0275; open Sunday to Friday, 10 a.m. to 5:30 p.m. and Saturday, 9:30 a.m. to 5:30 p.m.) for a tour and some sweet treats. For something more adult, visit San Sebastian Winery for a free tasting. (157 King Street; 904-826-1594; open Monday to Saturday, 10 a.m. to 6 p.m.; Sunday 11 a.m. to 6 p.m.)
Anastasia Island and State Park: Nature-lovers are drawn to Anastasia State Park (300 Anastasia Park Road; 904-461-2033; open daily 8 a.m. to sundown) for its 4 miles of pristine beaches and excellent bird-watching. You might see royal terns, brown pelicans, black skimmers, great blue herons and more. You can hit the beach, rent a kayak or canoe, or even go fishing and kiteboarding in the park. Beach-lovers also flock to Crescent Beach (50 Cubbege Road), on Anastasia Island. The hard-packed sand makes it ideal for a long walk or bike ride. Since you're on Anastasia Island, visit the nearby St. Augustine Lighthouse and Museum (100 Red Cox Road; 904-829-0745; open daily except Christmas Day and Thanksgiving Day, 9 a.m. to 6 p.m.). Yes, it's 219 steps to the top of the lighthouse, but the panoramic views will be your reward.