This small museum near the Plaza de Armas is the home of Juanita, also called the Ice Maiden — one of the best-preserved Inca mummies in the world. She was a young noblewoman sacrificed on the summit of Mount Ampato around 1450 as part of a capacocha ritual, and was discovered in 1995 when an eruption of the neighbouring Sabancaya melted the ice that had preserved her. The skin, hair, internal organs, and even her embroidered textile bundle have survived almost intact.
The museum visit is mandatory-guided (a guide is included in the ticket price), and the tour ends with Juanita herself in a refrigerated glass case. Photographs are not allowed in her room. Juanita rotates with a second mummy named Sarita and a long-running documentary about the discovery. Allow an hour; come early to avoid the post-lunch tour-bus crowds.