The largest U.S. Virgin Island, St. Croix, was originally founded by the Danish. Naturally, it abounds with beaches, water sports and sightseeing opportunities. But it also offers the visitor two fascinating towns. Christiansted, the largest, has an impressive historic district, outdoor market and bustling harbor. Seventeen miles away, Frederiksted, another harbor town, delights with Victorian architecture, a fort, even an aquarium. The European charm of these cities creates a enchanting contrast with the island's tropical beaches, bluffs, harbors, cays and coves.