Olympic National Park (Washington)
Credit: Justin Bailie / Getty Images

Olympic National Park protects one of the lower 48's longest and most primitive stretches of ocean shoreline, 65 miles of velvety sands, boulder-strewn beaches, and driftwood logs that meet the roots of coastal rain forest. The least crowded section is the 17.3-mile South Coast: Though there are barefoot-friendly parts, bring sturdy shoes to help you rock-hop over starfish-filled tidal pools and climb ladders to the overland passes. Don't forget a hard container to keep raccoons from stealing your food as you camp at the edge of the Pacific. And remember binoculars for the migrating whales, otters, and bald eagles, and the jagged seastacks that break the surf. [$5 for a backcountry permit, camping from $10 a night; nps.gov/olym]