Virgin Islands National Park
Preserving natural environments that cover more than two-thirds of St. John, Virgin Islands National Park is a must-see, even if you only have time to visit for a day. Explore plantation history at Annaberg Sugar Mill and Catherineberg Estate ruins, or do some bird-watching along a boardwalk through mangroves at Francis Bay. If you're interested in snorkeling, head to Salt Pond Bay or Trunk Bay, which has an underwater snorkeling trail. Pick one of the more than 20 trails on the north and south shores, and go for a hike.
A full-day trip to Reef Bay is a highlight. Although it's an easy hike through lush and dry forest, it can be a bit arduous for young kids. The nonprofit Friends of the Virgin Islands National Park ( friendsvinp.org) runs a $75 per person ranger-guided tour to Reef Bay that includes a safari bus ride to the trailhead and a boat ride back to the park visitor center. The schedule changes from season to season, and reservations are essential.
If you want to stay overnight, Cinnamon Bay Resort & Campground, inside the park along the island's north shore, has eco-tents and cottages in addition to bare sites. Regardless, stop by the Cruz Bay park visitor center to get oriented; pick up trail maps; and find out about guided walks, cultural presentations, and other park-service programs.