The Guanajuato mummies were discovered in the cemetery of Guanajuato, a city northwest of Mexico City. [B]etween the years 1865 and 1958 when a local law required relatives to pay a kind of grave tax.
You could pay the tax once (170 pesos) and be done with it; this option may have appealed to wealthier individuals. But you were also allowed to pay a yearly fee (50 pesos).
However, if the relatives could not pay this yearly tax for three years, the body (which had, by the way, become accidentally mummified) was dug up from the cemetery and placed on display in El museo de las momias.
The Mummies of Guanajuato are a number of naturally mummified bodies interred during a cholera outbreak around Guanajuato, Mexico in 1833.
Many of the bodies were buried immediately to control the spread of the disease; in some cases, the dying were buried alive by accident. As a result, some of the mummies have horrific expressions attesting to their death in the tombs, though most expressions became fixed postmortem.
There are 119 mummies currently on display, although only 2% of the corpses dug up had actually become mummified.