Speaking of ancient ruins, Machu Picchu is arguably one of the most well-known ancient ruins of all time. This Inca citadel is located in the Cuzco Region in modern-day Peru, and it stands 7,970 feet above sea level. Although the exact original use of Machu Picchu is unknown, most historians think that it was originally meant to be an estate for Pachacuti, the Inca emperor. It is estimated that it was built in 1450, but it was abandoned by the Incas during the Spanish Conquest. The three main components of Machu Picchu are the Inti Watana (a ritual stone), the Temple of the Sun, and the Room of the Three Windows. This classical Inca site wasn’t in the best shape when it was first brought to public attention in 1911, but it has been the center of diligent restoration efforts for decades.