The Museum of High Altitude Archaeology in Salta is the home to three mummified children which were found on top of the Llullaillaco volcano. These children were sacrificed to appease the gods. They weren’t deliberately mummified but the intense cold preserved them for over 500 years. The museum shows only one of them at a time. We saw ‘The Boy’. The museum has other things but it is a kind of ‘one big exhibit’ museum. As well as the body itself there’s a lot of information on how it was recovered and what they know about it. Worth a look if ever in Salta. Also a link to a BBC piece.
https://bbc.com/travel/article/20140122-the-children-of-llullaillaco