3-Nights Florida Everglades & Biscayne National Parks Multisport from $2,129

Biscayne National Park, just 25 mi/40 km south of Miami, Florida, protects and preserves a significant marine ecosystem that includes a shallow bay, undeveloped islands and coral reefs. The islands are the northernmost of the Florida Keys (though they are not directly connected to the other Keys by road) and contain tropical hardwood forests in their interiors. East of the islands lie coral reefs that support a colorful kaleidoscope of plants, fish and other sea creatures. The mangroves that line the bay draw birds, lobsters, sea turtles and manatees.

To reach the park, drive Highway 1 from Miami and then take S.W. 328th Street to Convoy Point and the park headquarters. The easiest way to see the park's underwater riches is aboard the glass-bottomed boat called the Reef Rover, but if you have time, by all means try a snorkeling or scuba-diving excursion to Boca Chita Key or Shark Reef—it's an unforgettable experience. While in the area, you may want to stop at Coral Castle. This strange labor of love is a collection of enormous sculptures and structures hewn by one man as a tribute to the woman who jilted him.

The Convoy Point and Dante Fascell visitors centers provide valuable information, as well as gift shop kiosks with food, drinks and souvenirs. Canoe and kayak rentals are also available. Phone 305-230-1100. http://www.biscayneunderwater.com.

Comprising 2,354 sq mi/6,097 sq km and located 40 mi/60 km southwest of Miami, Everglades National Park, Florida, is made up of tropical mangroves, freshwater marshes and forest, and is home to alligators, manatees, beautiful birds, the rare (and rarely seen) Florida panther and a wide variety of wetland flora.

The Everglades is a marvelous park, but its fragile ecosystem is threatened by increased residential development and agriculture. (Both were encouraged by an Army Corps of Engineers project begun in the 1940s that was intended to control the waters of the wetland.)

There are three entrances to the park: one near Florida City, one (the Shark Valley entrance) off the Tamiami Trail (Highway 41) and one near Everglades City on the Gulf coast. Take the main entrance near Florida City to get the best look at the park: Highway 9336 runs 35 mi/55 km across the preserve, from the headquarters and visitors center to the Flamingo Visitor Center.

Climb the observation tower at Pa-Hay-Okee Overlook, then stroll some of the boardwalks over the swamps and take some of the trails that run through dense woodlands. For a better view, take one of the park's canoe tours or go on a swamp tromp—a ranger-led hike through the marsh (wear old clothes). Be aware that vast hordes of mosquitoes are in the park in the summer, so take plenty of repellent along. Better yet, visit in the winter, especially if you're considering a canoe or kayak trip.

You should plan on taking two days to see the park via the Florida City entrance. You can camp within the park, or stay in nearby Homestead. The Everglades International Hostel in Florida City offers a unique lodging experience, as well as tours of the area (phone 305-248-1122, toll-free 800-372-3874; http://www.evergladeshostel.com). Those with less time may want to head for the Shark Valley entrance. There, a naturalist-narrated tram tour provides a two-hour introduction to the Everglades.

If you have the time and inclination, consider an extended canoe or sea kayak excursion. It's a great way to observe the subtle wonders of this complex ecosystem. The 100-mi/160-km waterway that runs from the Flamingo Visitor Center to near Everglades City is a popular place for day trips and overnight outings. It's also possible to rent a houseboat at Flamingo Marina. Toll-free 866-628-7275.

You might also want to visit nearby Big Cypress National Preserve, the ancient home of the Seminoles and the Miccosukees, just north of Everglades National Park. Activities include camping, fishing, hiking and swimming. To learn more about the Seminoles, head farther north to the Big Cypress Seminole Indian Reservation. The Ah-Tha-Thi-Ki Museum there showcases tribal artifacts and other displays on Seminole history. A nature trail leads to the reservation's ceremonial grounds.

Boat and canoe excursions and other activities are offered in the park by Everglades National Park Boat Tours. http://evergladesnationalparkboattoursgulfcoast.com.

Many visitors to the Everglades are interested in riding an airboat, a flat-bottomed vessel powered by an airplane engine and propeller mounted on the back of the boat. Be aware that they are banned within the national park itself because of the noise they make and the damage they do to vegetation. Airboat rides are available in portions of the Everglades outside the park, along Highway 41, also known as the Tamiami Trail, between Miami and Naples.

An adventure singular to the Everglades is a swamp buggy ride, where large, open-air vehicles with oversize tires take you on a bumpy but fun 90-minute ride through the woodlands. Those rides, too, are available outside the park at the Miccosukee reservation area and elsewhere along the Tamiami Trail (Highway 41). https://village.miccosukee.com.