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 Giluwe the vast alpine plateau, creeping "Astelia", cushion plants and mosses can be found near the numerous tarns, along with alpine blueberries ("Vaccinium") and asters in rockier areas. Mount Giluwe Mount Giluwe is the second highest mountain in Papua New Guinea at (Mount Wilhelm being the highest). It is located in the Southern Highlands province and is an old shield volcano with vast alpine grasslands. Ancient volcanic plugs form its two summits, with the central peak the highest and an east peak about away at . Giluwe has the distinction of being the highest volcano on the Australian continent and Oceania,