Florida is the second smallest municipality of Puerto Rico, with an area of 10 square miles. As the only municipality in Puerto Rico that has its urban area within the northern karst region (sometimes referred as the Northern Karst Hills), it is surrounded by low elevation, red clay and limestone haystack hills known in Caribbean Spanish as mogotes. The southern border of the municipality with Ciales remains one of the least developed areas on the island, due to the ruggedness of the karst. The Río Encantado, a subterranean river, drains this area. Several caves are found in the town, including Román Cave, Miró Cave, and Juana Gómez Cave. Balcon Cave (Cueva Balcón) is located in Florida.