The Southeast Mexico is a region of United Mexican States, formed by the states of Yucatán, Campeche, Quintana Roo and Tabasco. The area is almost flat, except for the presence of the hills and mountains that form the Sierra Atravesada. The mountains are about 250 km in length, and its highest point is in the passage of Chivela, about 2500 of elevation. Further east, near the boundary between Oaxaca and Chiapas, is the Cerro Azul, reaching an elevation of 2300.