There is a British cave system in the Midlands that some believe may contain an entrance to "hell." Experts discovered a multitude of caves within the Creswell Crags which are covered in hundred of witches' marks, originally thought to be nothing more than graffiti. These "apotropaic" marks were used across time to protect and ward against evil spirits. A set of these around a particular, four-foot hole suggests that locals thought it was a doorway to some kind of "underworld." The director of the Creswell Crags told the Daily Telegraph that the marks were most likely added when people thought that illnesses or crop failures were linked to the caves, and the underworld entrance in general. Tours of the caves will begin for the first time later this month.