The Children of Llullaillaco (Spanish pronunciation: [ʝu.ʝai̯.ˈʝa.ko], approximately: you-yai-YAH-koh), also known as the Llullaillaco mummies or the mummies of Llullaillaco, are three Inca child mummies rediscovered in 1999 by Dr. Johan Reinhard and his archaeological team on 16 March 1999 near the summit of Llullaillaco, a stratovolcano of 6,739 metres (22,110 ft) elevation in the Andes mountains along the border of Chile and Argentina. The children were sacrifices in an Inca religious ritual that is believed to have taken place approximately 500 years prior to the 1999 rediscovery. In this ritual, the three children were allowed to fall asleep on top of the mountain, and then they were placed inside a small chamber 1.5 metres (4.9 ft) beneath the ground, where they were left to die. According to Dr. Reinhard, the mummies "appear to be the best preserved Inca mummies ever found", and other archaeologists have expressed the same opinion, calling them among the best preserved mummies in the world. Since 2007, the mummies have been on exhibition in the Museum of High Altitude Archaeology in the city of Salta in north-western Argentina.
The Inca Empire (Quechua: Tawantinsuyu, lit. "The Four Regions"), was the largest empire in pre-Columbian South America. The empire started in the area around the city of Cusco, high in the Andes Mountains in modern-day Peru, in the 13th century. The Inca civilization did not expand much geographically until the mid-15th century. However, starting under the rule of Pachacuti in 1438, the Inca swept throughout South America along the Andes mountains, consolidating a massive land empire within the span of less than a century. The area that is now northern and central Chile, and north-western Argentina, was conquered and incorporated into the Inca Empire under the reign of Túpac Inca Yupanqui, who ruled as the second Sapa Inca, or Inca emperor, from 1471 to 1493. The Inca Empire reached its maximum geographical extent around 1530, and then began a rapid decline culminating in the fall of Cusco, the capital city, in 1533, along with the execution by conquering Spaniards of the emperor Atahualpa.