Lucky shoes. (Photo: Courtesy of the Cambridge Archaeological Unit/Used with Permission)

Maintenance workers at Cambridge University were just trying to run some new electrical cables in the walls of St. John’s College, when they stumbled upon a 300-year old shoe hidden in the wall. According to a story on Live Science, it was probably put there to ward off demons.

The lucky shoe is thought to date back to the 1600 to 1700s, probably put in place during a latter day renovation of the building. It is a left shoe, approximately a men’s size 6 by today’s measuring. While it had grown delicate with age, the shoe had remained remarkably preserved, still showing signs of original wear, including a hole in the sole indicating that it got a life of wear before it was bricked up in the wall.

Today the area where the shoe was discovered is a lunch or study room, but during the era that the shoe was likely put into place, it was probably used by the Master of the College. The shoe was likely placed in the wall to provide him with protection from evil, and may have even originally belonged to him. (The superstitious tradition of hiding shoes in the walls, goes back to the 1300s, and secret good luck shoes have been found everywhere from churches to insane asylums.)

Surprisingly, the Cambridge shoe is not headed for a museum. Instead, the maintenance crew just put it right back in the wall, adding a small time capsule with coins and a newspaper. The university has a long tradition of leaving signature mementos in the walls of their historic buildings during renovations. But it’s been a long time since they left a shoe.