It's been voted as one of Mexico's best tourism attractions – but it's not one for the faint-hearted.
More than 4,000 visitors turn up every week to the Guanajuato Mummy Museum, which must rank as one of the most macabre and grotesque in the world.
Tourists pay £2 for a guided tour to see more than 100 dried human corpses all of which have been taken from the cemetery next door.
There are murder victims, criminals who were buried alive and infants laid to rest dressed up as saints – a Mexican belief that it will ease their passage to heaven.
The mummies are a parchment-yellow colour, their dried skin moulding around the bones which lie beneath the surface. The thinner areas of skin – such as the eyelids, genitals, cheeks and earlobes – have deteriorated faster, and in most cases little remains but flaky scraps and gaping holes.
The human remains have been preserved due to the method of burial in the Saint Paola Cemetery next door. Corpses, rather than being buried in the ground are sealed inside air-tight crypts, where the lack of oxygen slows the natural rate of decomposition.
"The bodies dry out rather than putrefy, which leaves them in this state of mummification," says Jesús Saltillo, one of the tour guides at the museum.
Many of the corpses are so well preserved that their eyebrows, beards and fingernails are still intact. Nearly all of the mummies' mouths are gaping open, a result of the hardening of the tongue and slackening of the jaw muscles following death.
"It leaves them all with an expression as if they were experiencing terrible pain", says Jesús, "but the vast majority died peacefully."
Those mummies who didn’t die "Holy Deaths" – as the Mexicans describe the act of dying in one’s sleep – are displayed in a separate section of the exhibit.
The Saint Paola Cemetery, the museum’s source of mummified remains next door, is made up of entire walls of individual crypts, seven tombs high.
Those which are occupied are bricked up from the outside and sealed with a placard denoting its occupant, those which are empty leave dark square holes in the flower-decked facade.
When a family’s lease on their loved one’s crypt expires, they are given five days to renew the payment (£95 for twenty years). If they choose not to pay, the body is removed and given to the museum’s curator for inspection.
If the curator finds its condition good enough to appeal to the huge numbers of visitors his museum receives, it is added to the collection. If rejected, the body is sent to a common grave on the outskirts of town.
The first ever mummy to be disinterred was Remigio Leroy, known as the "French Doctor". A Frenchman who died during a visit to Guanajuato in the 19th century. The body was disinterred after twenty years inside a crypt in 1865, when the owners were amazed to find his almost-perfect preservation.
His condition, complete with the clothes he still wears for visitors today, aroused so much excitement in the mining town that the cemetery began to collect other well-preserved corpses for display, eventually establishing the dedicated museum in the 1950s.
The museum is renowned for its ownership of the smallest mummy in the world – a four-month-old foetus of a woman who fell victim to a cholera outbreak in the 1860s.
The foetus, no bigger than a pound coin, was found preserved still inside its mother’s womb when she was removed from her crypt and is today examined by visitors through a magnifying glass fixed above it.
The most recent addition to the collection was Baby Enrico, an infant who died at six months of age in 1999.
The museum is open seven days a week, although it closes for a day every two months in order to clean the mummies, many of whom are still wearing the clothes they were buried in.
“The clothes begin to rot before the bodies do," says tour guide Manuel Limón. “It’s vital that they are maintained."
Those cadavers which are undressed display the yellow skin, shrivelled eyeballs and gaping mouths of Hollywood zombie movies. Indeed, multiple Mexican horror movies have been made using the mummies as props.
The most famous, El Santo vs. The Mummies of Guanajuato, features the most famous wrestler from the country’s popular "lucha libre" sport, taking on the mummies as they come to life, executing perfect pile-drivers into their dried forms.
Perhaps unsurprisingly, not everyone enjoys their visit.
Peruvian visitor Maria Goncalves says in the middle of her group’s guided tour: "It’s terrifying, I feel sick to my stomach. It’s the terrible expressions the mummies all have that makes it so horrible."
And despite the museum’s macabre exhibits, guided tour groups of 15 or more pass through its hallways every ten minutes.
“We see even more on weekends," says Jose Martínez, who sells souvenir sugar effigies of the dried human remains at the museum’s exit. “Usually on Saturdays there’s an hour-long wait just to get in."