In the mines of highland Bolivia, "El Tío" is the familiar name for the spirit owner of the mountain, who is also known as Huari or Supay. The words "El Tío" are Spanish for "the uncle" and evince the relationship of patronage that the miners have with the spirit. He is associated with pre-Hispanic nature spirits as well as the Christian Devil and is a central figure in the ritual life of Bolivian mining communities. An icon of El Tío is situated in each mineshaft to receive sacrificial offerings of alcohol, coca, cigarettes, llama blood and other ritual items from the miners in return for his goodwill and his guarantee of good health and good fortune in the mines.
For more information, read en.citizendium.org/wiki/El_T%C3%ADo
Candelaria silver mine - Potosi (Bolivia)