The Seven Third Summits are the third-highest mountains of each of the seven continents. All of these mountain peaks are separate peaks rather than a sub-peak of the continents' high point. Christian Stangl from Austria claims to be the first person to reach the summit of all seven third summit mountains after climbing Puncak Mandala and Puncak Trikora. He did this as a part of his "Triple Seven Summits" project. Because of glacial melting and the disagreement over exactly which three peaks are the tallest in the Australian continent, Stangl also climbed several additional candidate peaks including Sumantri (4,870 m (15,978 ft)) and Ngga Pulu (4,862 m (15,951 ft)).[1][2]