The Volcanic Seven Summits are the highest volcanoes on each of the seven continents, just as the Seven Summits are the highest peaks on each of the seven continents. Summiting all seven is regarded as a mountaineering challenge, first postulated as such in 1999. Two of the Volcanic Seven Summits are also in the Seven Summits list. Mount Kilimanjaro and Mount Elbrus, which were formed volcanically, are the highest peaks of their respective continents. Definitions Due to different interpretations of continental borders (geological, geographical, geopolitical) several definitions for the highest summits per continent and the number of continents are possible. The number of seven continents used here is based on the continent model used in Western Europe and the United States. An additional complication in determining the highest volcanic summits is defining exactly what constitutes a volcano and how much topographic prominence it must have relative to any nearby non-volcanic peaks in order to qualify. For the purposes of this list, the summits must be an actual eruptive volcanic center, not merely made of volcanic rocks which were uplifted by other geological processes. In addition, a topographic prominence of at least is required, so that the list includes only genuine volcanic mountains and not minor outpourings of lava which happened to leak to the Earth's surface in high-altitude regions (see Asia below). Africa, North America, Antarctica No serious dispute exists as to the highest volcanoes in Africa, North America, and Antarctica—respectively, Kilimanjaro, Pico de Orizaba, and Mount Sidley. Australia Although there are a few minor and inactive volcanoes on the Australian mainland, this list recognizes that the island of New Guinea is part of the Australian continent. Numerous scientific papers written in the 1970s and 1980s confirm that Mount Giluwe in Papua New Guinea is in fact an old eroded volcano, unlike the higher mountains of New Guinea which are all non-volcanic in origin. Even if this continent is defined instead as Oceania (thus adding New Zealand and Polynesia including Hawaii), Giluwe remains the highest volcano since it exceeds the elevation of Mauna Kea in Hawaii and any volcano in New Zealand. Europe The generally accepted geographical border between Europe and Asia runs along the crest of the Ural Mountains in central Russia and of the Caucasus along the southern border of Russia. Since the massive twin-peaked stratovolcano of Mount Elbrus rises just north of the crest, it is the