One of the three caponiers, or covered passages, that were built across the moat in 1853 for local defence.

Situated at the end of a 2.4km shingle spit that extends into the western Solent from Milford-On-Sea, Hurst Point is the closest part of the mainland to the Isle of Wight. Accessible only by boat or on foot, it is the location of Hurst Castle, one of Henry VIII's chain of coastal defences, completed in 1544. The castle was used as a prison for eminent 17th century captives, and was later strengthened during the 19th and 20th centuries.