Note: many comments refer to directions, like north, east, etc. For these, assume the lagoon is east. If you are going by a compass, the lagoon does not run exactly north/south. If you have a GPS unit, the fort is at 18°40.627N, 88°23.309W.
At the bottom of the moat that surrounds the Fort, sharp pointed stakes were placed to reinforce its defensive power.
The main part of the fort is a wonderful Museum that includes information on the Mayan culture, Pirates, and the War of the Castes. It is definitely worth a trip to Bacalar to see the Fort of San Felipe and its great Museum.