Ambergris Caye is the largest island of Belize, located northeast of the country's mainland, in the Caribbean Sea. It is about 40 kilometers long from north to south, and about 1.6 kilometers wide. Where it has not been modified by man, it is mostly a ring of white sand beach around mangrove swamps in the center. Reef divers enjoy the Belize Barrier Reef and the Blue Hole, a 400-feet deep circle of limestone.