Verne Citadel is a citadel on the Isle of Portland, Dorset, England. The citadel was started in 1847 at a camp for prisoners building Portland harbour's breakwaters, and was extended during the 1860s as a result of the Royal Commission, ending up with 8 RML guns with calibres up to 12". It is now used as a prison — The Verne, with no public access. Following WWII the Citadel was used for training newly conscripted recruits of the corps of the Royal Engineers. The moat was used for training in the use of explosives. When conscription ended in Britain circa 1963 the Citadel reverted to its former use as a prison.