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
Highest unclimbed mountain Highest unclimbed mountain An unclimbed mountain is a mountain peak that has yet to be climbed to the top. Determining which unclimbed peak is highest is often a matter of controversy. In some parts of the world, surveying and mapping are still unreliable, and there are no comprehensive records of the routes of explorers, mountaineers and local inhabitants. In some cases, even modern ascents by larger parties have been poorly documented and, with no universally recognized listing, the best that can be achieved in determining the world's highest unclimbed peaks is somewhat speculative. Most sources indicate that Gangkhar Puensum ()