Machu Picchu transport of this obsidian type in pre-Hispanic Peru. Thousands of tourists walk the Inca Trail to visit Machu Picchu each year. They congregate at Cusco before starting on the one-, two-, four- or five-day journey on foot from kilometer 82 (or 77 or 85, four/five-day trip) or kilometer 104 (one/two-day trip) near the town of Ollantaytambo in the Urubamba valley, walking up through the Andes to the isolated city. Machu Picchu is both a cultural and natural UNESCO World Heritage Site. Since its discovery in 1911, growing numbers of tourists have visited the site each year, including 1,411,279 in 2017.
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