Trunk Bay

A white-sand beach on St. John in Virgin Islands National Park with an underwater trail: signs placed along about 400 feet of water explain the animals that depend on the coral beneath you, which makes it a good first reef for children and nervous swimmers. Entry costs $5 for visitors 16 and over, paid by card or phone, and snorkel gear can be rented on site. Stand only on sand, because the trail runs over coral that does not survive being trampled.