The domain of hardcore fishermen and duck hunters, with fewer than 13,000 visitors a year, this 19-mile-long barrier island is the remotest part of Cape Lookout National Seashore. Take the ferry ($75 per car, plus $14 per person) from the town of Atlantic, and ask the island caretaker to arrange drop-offs of bait and icethe inlets teem with red drum and flounder. Rent one of 12 solar-powered cabins (from $110; portsmouthislandfishing.com) perched among the sea oats.
Padre Island National Seashore, TX
This is not the tequila-infused spring-break hot spot of the same name. The bottom 70 miles of North Padre Island are empty, save for some fishermen and sea turtles. From Corpus Christi, take South Padre Island Drive south, cross the bridge, and stop at the visitor center to register. Keep going on to South Beach, a 55-mile stretch of sand that's technically a state highway (four-wheel drive is essential). Pitch a tent dune-front, look across the Mansfield Channel, and thank God there are miles between you and Girls Gone Wild XXXV.
Shi Shi Beach, WA
To reach the end of the country, you have to walk a planka three-mile wooden footbridge that starts on the Makah reservation, 2.5 hours northwest of Seattle on Highway 112. Buy wine before entering the reservation, which is dry, and buy a seafood-harvesting tag once you're there (try Washburn's General Store, in Neah Bay). Park at the trailhead just before the fish hatchery on Route 112, walk down the footbridge, switch back a few times through the mud, and there it is: the most northerly tip of Olympic National Park, a two-mile-long beach broken up by tall black sea stacks (wilderness permits, nps.gov/olym). Your neighbors are smart surfers who've come for Makah Bay's six-foot swells.
Cape Cod National Seashore, MA
Even in August, when some 850,000 sun-seekers swarm its beaches, you can find pockets of empty on Cape Cod National Seashore. But it becomes a true oasis in winter, when many of the 115 beaches and 560 miles of coastline are abandoned. The off-season also means free parking, cheaper lodging, and access to beaches closed to non-residents in summer. Catch a chilly sunrise at Race Point Beach, just over the sand dunes from Provincetown. For 15 miles' worth of stunningly good winter mountain biking, hit the loop-de-doo Trail of Tears, accessed from a parking lot along the service road near the intersection of Routes 6 and 149.
Sinkyone Wilderness State Park, CA
"Lost Coast" is no misnomer. This is a hiking trip in which the only invitees are you, the bears and elk, and the cliffs hanging 1,200 feet over the beach. The majority of the 22-mile Lost Coast Trail sits within Sinkyone Wilderness State Park, which starts at Usal Beach (200 miles north of San Francisco) on the southern end. Take a tide chart and catch the shuttle (lostcoasttrail.com) to Needle Rock Visitor Center, at the north end. Then start walkingit's 17 miles back to Usal, and the trek is best done in two days. Crash at the cliff-framed Little Jackass Creek campsite ($15; parks.ca.gov).
Milolii Beach, HI
One reason Kauai's famed, movie-set-ready Na Pali Coast remains kinda remote? You can't drive there. Head to Milolii, Na Pali's hardest-to-reach beach, at the beginning of the season (mid-May) and you'll beat the kayak tours that stop here for lunch. Launch from Haena State Park beach and sea-kayak the 13 miles to Miloliiit's the mile-long white thing framed by 2,000-foot mossy cliffs (guides are a must; $372 per day, transportation from $75; kayakkauai.com). Hike ten minutes up the valley to the Lomi Lomi Waterfall, then retreat to your beach camp (permits, $10; hawaiistateparks.org/parks/kauai).