Less than a half hour south of Belmopan, the 575-acre St. Herman's Blue Hole National Park has a natural turquoise pool surrounded by mosses and lush vegetation, wonderful for a cool dip. The "inland Blue Hole" is actually part of an underground river system. On the other side of the hill is St. Herman's Cave, once inhabited by the Maya. There's a separate entrance to St. Herman's. A path leads up from the highway, but it's quite steep and difficult to climb unless the ground is dry. To explore St. Herman's cave beyond the first 300 yards or so, you must be accompanied by a guide (available at the park), and no more than five people can enter the cave at one time. With a guide, you also can explore part of another cave system here, the Crystal Cave (sometimes called the Crystalline Cave), which stretches for miles; the additional cost is BZ$20 per person for a two-hour guided tour. The main park visitor center is 12.5 miles (20.5 km) from Belmopan. The park is managed by the Belize Audubon Society, which administers a network of seven protected areas around the country.