Machu Picchu
Machu Picchu is very difficult to get to because it is so high in the mountains. It has only one way in and a stone wall to protect it. Most people on Earth did not know it was there until a Yale graduate named Hiram Bingham rediscovered it in 1911. He heard rumors of a hidden city which was already known to the native Peruvians, who guided him there. He led a restoration project that was partly funded by the National Geographic Society. Bingham made a deal with the government to take artifacts to the Peabody Museum for study. Peru is still trying to have those artifacts returned to them.