The Slaves' Prison (Italian: Prigione degli Schiavi, Maltese: Il-Ħabs) officially known as the Gran Prigione and colloquially as the bagnio, was a prison in Valletta, Malta. It was established in the late 16th century, and remained in use as a prison throughout the 17th and 18th centuries. It was subsequently used as a naval hospital, a school and an examination hall. It was bombed in World War II, and the ruins were demolished to make way for a block of flats.