Beneath and alongside the Santuario del Socavón, the anthropological and mining museum occupies the tunnels and chambers of the original mine. The collection covers the pre-Columbian cultures of the Bolivian altiplano, the history of Oruro's mining industry, and the religious traditions that grew up around it.
The most compelling section is the underground exhibit on mining ritual — specifically the worship of El Tío, the devil-figure kept in every active Bolivian mine. The museum explains the syncretism between Catholic devotion to the Virgen del Socavón (above ground) and pre-Christian propitiation of El Tío (below ground), which are two halves of the same religious system.
The Carnaval de Oruro is also documented extensively, with full carnival costumes and masks on display. Small admission fee; located under the Santuario del Socavón.