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.