Hatillo is a town and municipality located in Puerto Rico's north coast, bordered by the Atlantic Ocean to the north, Lares and Utuado to the south, Camuy to the west, and Arecibo to the east. According to the 2000 US Census Hatillo is spread over nine barrios and Hatillo Pueblo. It is part of the San Juan-Caguas-Guaynabo Metropolitan Statistical Area.

The Northern Karst Belt is a limestone karst landscape located in the northern part of Puerto Rico. A karst is a topographical zone formed by the dissolution of soluble porous rocks, such as limestone, with features such as mogotes, canyons, caves, sinkholes, streams and rivers, all of which are common on this region of the island. Some of the island's main rivers, including its longest, traverse the karst and form some of the most distinctive Puerto Rican geographical features such as the Camuy caverns. Many of these rivers feed into and are important in the formation of many marshy areas such as the Caño Tiburones wetlands.