The southern coast of St.Thomas is endowed with the attractive and protected Mangrove Lagoon Wildlife Sanctuary & Marine Preserve of exceptional natural resources and is filled with scenic contrasts: manglar islands, rocky cliffs, shallow clear waters with sea grass beds, salt ponds and panoramic ridge lines. 

These natural areas provide a rich nursery habitat for offshore coral reef fish and invertebrates, and homes to nesting egrets, pelicans, herons and terns.  This gentle tour affords recreational and educational opportunities for persons of all ages and abilities. 

As an important part of the Virgin Islands Park System, Cas Cay is a 15 acre Wildlife Preserve for white-cheeked pintail ducks, red-billed and white-tailed tropic birds, Brown pelicans, oyster catchers, roseate terns, egrets, herons and sandpipers.

A special and rare dry forest ecosystem of mampo, sea grape and ink berry begins at the south side volcanic cliffs and extends into a flat, sandy area with a red mangrove forest, complete with a village of hermit crabs.