Mount Sidley is the highest dormant volcano in Antarctica, a member of the Volcanic Seven Summits, with a summit elevation of 4,181–4,285 metres (13,717–14,058 ft).[1][2] It is a massive, mainly snow-covered shield volcano which is the highest of the five volcanic mountains that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a 5 km wide caldera[3] on the southern side and stands NE of Mount Waesche in the southern part of the range.