The Bentley Subglacial Trench is a vast topographic trench in Marie Byrd Land, West Antarctica, 80°S, 115°W. At 2,555 meters (8,382 ft) below sea level, it is the lowest point on the surface of the earth not covered by ocean, although it is covered by ice. Most people do not count it as the lowest point on land, since the overlying ice sheet makes it essentially subterranean. (See Extremes on Earth and Vestfold Hills)[who?] Also, if the ice melted, the area would be under water. The trench's size is similar to that of Mexico.[citation needed]