Marie Byrd Land
Antarctica is divided down the center by the Transantarctic Mountains. The land west of these mountains includes the narrow Antarctic Peninsula, the Ellsworth Mountains, and the region which comprises the majority of the remaining land, Marie Byrd Land. Throughout Marie Byrd Land, there are many exposed volcanic rocks with peaks greater than 11,000 feet. The highest mountains are extinct volcanoes with the classic symmetrical profile and wide collapsed craters. Most of these rise along or near the western coast, rising above the Amundsen Sea. Mount Sidley (13,717 ft.) is the highest mountain of this region. Also of interest is Mount Siple (10,170 ft.), which rises from a small island offshore.