St. John is the smallest of the 3 U.S. Virgin Islands, which are located in the Caribbean Sea. Virgin Islands National Park occupies more than half the island. Its forests shelter resident and migratory birds, including cuckoos, warblers and hummingbirds. The mangroves at Hurricane Hole, in the east, support corals and anemones. Dolphins inhabit the island’s waters, which also host hawksbill and green turtles.