The Yucatán Peninsula is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the Caribbean Sea to the east. The Yucatán Channel, between the northeastern corner of the peninsula and Cuba, connects the two bodies of water. The peninsula is approximately 181,000 km2 in area. It has low relief and is almost entirely composed of porous limestone.