Guatemala is a country in Central America, south of Mexico. It is a mountainous country, except for the southern coastal area and the vast northern lowlands of Petén department. Two mountain chains enter Guatemala from west to east, dividing the country into three major regions: the highlands, where most mountain chains are located; the Pacific coast, south of the mountains; and the Petén region, north of the mountains. All major cities are located in the highlands and Pacific coast regions. By comparison, Petén is sparsely populated. These three regions vary in climate, elevation, and landscape, providing dramatic contrasts between hot and humid tropical lowlands and colder and drier highland peaks. Volcán Tajumulco, at 4,220 meters, is the highest point in Central America. Guatemala's abundance of biologically significant and unique ecosystems contributes to Mesoamerica's designation as a biodiversity hotspot.