Machu Picchu Base Admiralty Bay. Machu Picchu Base conducts annual scientific expeditions to Antarctica. The base carries out a variety of scientific projects such as research into krill and its potential as an alternative human food source, as well as geological, biological, hydrographic, and geophysical research, under the provisions of the Antarctic Treaty. The base operates radar measuring upper atmospheric winds, and supplying data on the deterioration of the ozone layer. As Antarctica is a continent of valuable strategic, ecological, and economic importance, Peru has an interest in maintaining its status as a non-militarized, nuclear-free zone of peace, and in preserving its environment,
Machu Picchu an Inca grass rope bridge, across the Urubamba River in the Pongo de Mainique, provided a secret entrance for the Inca army. Another Inca bridge was built to the west of Machu Picchu, the tree-trunk bridge, at a location where a gap occurs in the cliff that measures . The city sits in a saddle between the two mountains Machu Picchu and Huayna Picchu, with a commanding view down two valleys and a nearly impassable mountain at its back. It has a water supply from springs that cannot be blocked easily. The hillsides leading to it were terraced, to provide