Part of the Cape Cod National Seashore, Marconi is a narrow Atlantic beach backed by sea cliffs and undulating dunes. Facilities include changing rooms, restrooms and showers. It's named for famous Italian inventor Guglielmo Marconi, who sent the first transatlantic wireless message from a station nearby in 1903. Parking costs $20 in summer (the permit fee to access the National Seashore). The Atlantic White Cedar Swamp Trail is a 1.5-mile nature trail that's worth exploring.