Machu Picchu in South America, one of the most visited tourist attractions in Latin America and the most visited in Peru. Machu Picchu has wet and dry seasons, with the majority of annual rain falling from October through to April. Machu Picchu is situated above a bow of the Urubamba River, which surrounds the site on three sides, where cliffs drop vertically for to the river at their base. The area is subject to morning mists rising from the river. The location of the city was a military secret, and its deep precipices and steep mountains provided natural defenses. The Inca Bridge,
Machu Picchu push the stones up inclines. A few stones have knobs that could have been used to lever them into position; the knobs were generally sanded away, with a few overlooked. The Inca road system included a route to the Machu Picchu region. The people of Machu Picchu were connected to long-distance trade, as shown by non-local artifacts found at the site. For example, Bingham found unmodified obsidian nodules at the entrance gateway. In the 1970s, Burger and Asaro determined that these obsidian samples were from the "Titicaca" or Chivay obsidian source, and that the samples from Machu Picchu showed long-distance