PERU, Machu Picchu: Tucked away in the rocky countryside northwest of Cuzco, Machu Picchu is believed to have been a royal estate or sacred religious site for Inca leaders, whose civilization was virtually wiped out by Spanish invaders in the 16th century. The American archaeologist Hiram Bingham stumbled upon it in 1911. The site stretches over an impressive 5-mile distance, featuring more than 3,000 stone steps that link its many different levels.