The U.S. National Parks System is synonymous with mountains, rivers, and forests. But it also encompasses marine environments, including the coral reefs and pristine beaches of Virgin Islands National Park. Created by preservationist Laurance Rockefeller in the 1950s, Caneel Bay is set on a 170-acre peninsula on the northwest side of St. John and is the only hotel in the national park. Guests won’t find phones or TVs in any of the 166 rooms, suites, and cottages. The resort is a place to unplug and a base for exploring the island by land—miles of rain forest hiking trails lead to the remains of old sugar plantations and pre-Columbian petroglyphs—or by sea at one of the many snorkeling and scuba sites. From $409.