In South Florida, "down under" carries dual connotations for family adventurers: snorkeling or diving in the only coral reef system in the continental United States, and exploring the raw, alligator-infested, bird-flocked wilderness of the southern-lying Everglades stretching from Miami's back door. Homestead, Miami's tropical agricultural breadbasket, lies at the juncture of the reef and the wetlands known as the Everglades, which refers to the slow-moving "river of grass" for which national park was named. The 1.5-million-acre park is home to 'gators, crocodiles, Florida panthers, manatees, 350 species of birds, and 43 species of mosquitoes. That latter group of wildlife makes summer Everglades visits near-torture, so plan for winter, when wildlife spotting is best. Then head from the wetlands to the islands, starting at the Florida Key's northernmost point. Biscayne National Park consists of 172,924 acres, 95 percent of which lies under water. The park marks the beginning of the chain of reefs that extends south to the 220-mile-long Florida Keys National Marine Sanctuary, which includes the Tortugas islands and the submerged coral reef that extends six miles from the last island in the Keys.

Family Road Trippin'

CLICK HERE to view a map of this itinerary—and 19 other family-centric road trips across these United States. Florida Photo Gallery Florida Screensaver Everglades National Park

For families, these numbers translate into rich opportunities to see wildlife both below and above the surface of waters custom-made for paddling, glass-bottom boating, snorkeling, and diving.

Day 1: Miami to Everglades National Park (40 Miles)
From Miami, head west along Highway 41, aka Tamiami Trail, to the classic tourism and nature-immersion scene of north Everglades National Park (305.242.7700; www.nps.gov/ever) and adjacent 729,000-acre Big Cypress National Preserve (239.695.1201; www.nps.gov/bicy) via the Shark Valley Visitor Center (305.221.8776). Rent bikes (305.221.8455) and circumnavigate the 15-mile paved loop road to a spiraling 50-foot observation tower—if your family is energetic enough. And if they're brave enough; during the winter, you're likely to encounter alligators up close. But don't worry, they'll quickly to get out of your way. Otherwise, ride the tram for a two-hour tour. River otters sometimes seek the warmth of the pavement, while ospreys and bald eagles swoop high above.

Afterwards, stop at the Miccosukee Restaurant (305.223.8380 ext. 2374; www.miccosukeetribe.com) for 'gator tail, frog legs, and other typical Everglades fare. It's run by a Native American tribe that also operates the culture museum across the street. Or visit to a nearby hunting camp via airboat, the noisy, low-draft boats locals use for frogging and navigating shallow 'Glades waters.

For a scenic drive with lots of wildlife-spotting opportunities, take a left on Loop Road (County Road 94) to enter the backwoods of Big Cypress National Preserve. It starts out paved, but turns to dirt, at times washboard. Alligators stretch across the road, red-shouldered hawks screech from above, and huge soft-shelled turtles, otters, and raccoons make cameo appearances. Back on Highway 41, turn right to visit the preserve's Oasis Visitor Center. Stroll the boardwalk outside to spy huge alligators. Another good 'gator-spotting vantage point is the boardwalk at H.P. Williams Roadside Park to the west. Camp at nearby Monument Lake (239.695.1201), which has restrooms, an outdoor cold shower, drinking water, and tent and RV sites (but no hookups). Drive to Joanie's Blue Crab Café (239.695.2682) for swamp cuisine and ambiance.