Seven Third Summits Sumantri () and Ngga Pulu (). The definition of "continent" is a matter of some dispute among mountaineers seeking to complete this challenge. The main ridge of the Greater Caucasus range is generally considered to form the boundary between Europe and Asia. In that case, Mount Elbrus () and Dykh-Tau (), are the two highest mountains in Europe. Excluding the Caucasus Mountains, Mont Blanc () and Monte Rosa () would be Europe's two highest mountains. The Australian continent is defined as comprising the mainland of Australia and proximate islands on the same continental shelf, including Tasmania and New Guinea. In
Mount Elbrus the two summits but collapsed after only a few years. Its remains can still be seen. In 1939, the Soviet Intourist travel agency built yet another structure a little above the "Priyut 11" site at 4,200 metres, covered in aluminium siding. It was meant to accommodate western tourists, who were encouraged to climb Mount Elbrus in commercial, guided tours at the time to bring in foreign currency. Not much later, this hut was converted into a mountain barracks, serving as a base, first for Soviet and later German troops in the Battle of the Caucasus of World War II. On