What was a oubliette in medieval times?

An oubliette was a type of dungeon or prison cell used in medieval times, characterized by its narrow, often concealed entrance and a deep, vertical shaft. The term "oubliette" comes from the French Word "oublier," meaning "to forget," as prisoners were often left to languish and die without hope of rescue. These dark, isolated chambers served as a brutal means of punishment and imprisonment, reflecting the harsh realities of medieval justice.