It looks like the rest of the island did before civilization arrived - lots of palm trees and empty beaches.
When weather permits hire a boat to take you all round the island, starting in the back, heading north through the cut between Mexico and Belize, then down the front side - part of the trip going south in front is outside the reef an that can be dicey, but if weather is bad you can retrace your route and miss the excitement.
Xcalat is in Mexico, a few miles north of the boarder. It's a hassle to visit due to immigration protocol.