Florida Keys vs San Francisco

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.

San Francisco packs world-famous sights into a compact, hilly peninsula wrapped in fog and bay views. Ride a clanging cable car up Nob Hill, then drop toward the water for sourdough bread bowls of clam chowder at Fisherman's Wharf. Book Alcatraz well ahead, because the ferry to the former prison island and its gripping audio tour sell out weeks in advance. Walk or bike across the Golden Gate Bridge, coast downhill into Sausalito for seafood by the bay and ride the ferry home past the skyline. Give a full day to wine country, sipping Cabernet in Napa Valley or Pinot Noir in laid-back Sonoma, and save a morning for the towering coast redwoods of Muir Woods, where parking or shuttle reservations are required, or swap in the cliffs and beaches of Half Moon Bay. The city itself rewards slow wandering: dim sum in Chinatown, espresso in North Beach, murals in the Mission and sunset at Ocean Beach. Pack layers whatever the month, since summer fog can drop temperatures into the 50s while the sun shines a few miles inland, and wear comfortable shoes for the steep hills. September and October usually bring the warmest, clearest days of the year.