The colorful tradition with the skulls, known as "natitas," is rooted in ancient indigenous beliefs that is meant to bring good fortune and protection by honoring the dead.
The skulls are decorated and paraded to the cemetery a week after All Saints Day. The celebration is believed to have its roots in the Uru Chipaya custom of disinterring the bodies of loved ones at the one-year anniversary of their death.
"They are very miraculous. They are very dear little souls. They fulfill all the miracles, everything you ask of them," Melvi Mariscal, a believer in the ritual, said at a cemetery in the Andean city.
"They help you study, they help you at work, in your health. They are always protecting you and giving you a little hand."
The skulls were surrounded by candles and coca leaves, which many in the country chew for energy, garlanded with colorful flowers, fake hair, sunglasses, Andean hats, and even one with a small model of a Grim Reaper, the personification of death.
People in the cemetery remembered their loved ones and asked for protection and help for the year ahead. Some carried the skulls in decorative boxes.
"I tell him when we are sick, people in the family, I ask him to please heal us and he fulfills it," said Sofia Irusta, holding a skull with two cigarettes, a brown wig, and a crown of flowers. "Everything I ask him he fulfills. That is what I like about my skull."