best at night
The water temperature at Sand Beach, Acadia National Park’s popular swimming area, rarely exceeds 55 degrees, so don’t even think about skinny-dipping in those Maine waters. Far better to stroll at night—and bundled up—when the shimmering bioluminescence from microscopic creatures in the bay can sometimes illuminate the adjacent rocky bluffs. Pick up Ocean Path behind the beach restrooms for the 4-mile walk to Otter Point and back. Take it slowly in the dark. Lot parking is available, plenty of it after hours.