Florida Keys vs Utah Mighty 5

The Florida Keys are America's most famous road trip island chain, a necklace of coral islands linked by the Overseas Highway as it hops 113 miles from Key Largo to Key West over 42 bridges and turquoise water. Starting from Miami, you can be snorkeling North America's only living coral barrier reef at John Pennekamp Coral Reef State Park within a couple of hours. Farther south, Islamorada is the sportfishing capital with tarpon feeding at the docks, Marathon has a sea turtle hospital and the soaring Seven Mile Bridge, and Bahia Honda State Park offers some of the best natural beaches in the Keys. The road ends in Key West, a colorful, easygoing town of conch houses, Hemingway's cats, and the nightly sunset celebration at Mallory Square. This plan covers the full Key Largo to Key West run in four days, then adds a day trip by ferry or seaplane to remote Dry Tortugas National Park and its giant brick fort. Navigate by the green mile markers, slow down in Key deer zones, eat plenty of fresh fish and key lime pie, and book Key West hotels early in winter.

Utah's Mighty 5 is the classic Southwest road trip: five national parks strung across roughly 400 miles of red-rock desert, each completely different from the last. Start in Zion, where the Virgin River has carved a sheer sandstone canyon you explore by shuttle, then climb to Bryce Canyon's amphitheaters of orange hoodoos at more than 8,000 feet. Scenic Byway 12, one of the most beautiful drives in the country, carries you to Capitol Reef, a quieter park of cliffs, petroglyphs and pioneer orchards near the small town of Torrey. The trip ends in Moab, base for Arches and its 2,000-plus stone arches and for Canyonlands, where the Island in the Sky mesa looks down on the Colorado and Green rivers. Most travelers fly into Las Vegas or Salt Lake City, rent a car and spend about a week, sleeping in Springdale, Bryce or Tropic, Torrey and Moab. Plan ahead: Arches uses a timed-entry system in its busy season, Angels Landing needs a permit, and summer afternoons regularly top 100°F (38°C), so early starts, plenty of water and spring or fall dates make the biggest difference.