A lot of people make it a goal to climb the Seven Summits. The 'Seven Summits' are comprised of the highest mountains on each of the seven continents of the Earth: Everest, Aconcagua, Denali, Kilimanjaro, Elbrus, Mount Vinson and Carstensz Pyramid.
A more difficult challenge is the Seven Second Summits. The Seven Second Summits are the second-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. The Seven Second Summits are considered by many mountaineers and geographers as a much harder challenge than the traditional Seven Summits. This is due to their remote locations and are largely ignored in favor of higher mountains. The Second Seven are K2, Mt. Logan, Ojos del Salado, Batian, Mt. Tyree, Dych Tau, Dufourspitze, Sumantri, Ngga Pulu, Puncak Trikora, and Puncak Mandala.