In 2010 the former English Heritage Archaeological Survey and Investigation team undertook a detailed survey of Cliffe Fort, a coastal artillery fort built in the 1860s. The fort is located on the Hoo Peninsula, Medway, in the parish of Cliffe and Cliffe Woods, on the south side of the Thames. It is 3 km west of Cliffe village in the area of the former cement works. The fort is a Scheduled Monument and is on the Heritage at Risk register, where, due to flooding, vandalism and partial collapse, the condition of the structure is described as ‘very bad’. The fort has had little previous investigation and was identified as needing detailed research by the Hoo Peninsula Historic Landscape Project, a multidisciplinary landscape project which aimed to increase our knowledge and understanding of the peninsula in order to contribute to strategic decision-making. The survey results will inform the future management of the site and provide an enhanced designation base. Cliffe Fort was part of a large and expensive defence infrastructure programme undertaken in the 1860s and incorporated the latest in fortification theory and technology. It was one of the last casemated forts with iron shields to be completed. Investigation revealed that despite some almost immediate alterations to the basement magazines, a lack of alteration in the 20th century has preserved a number of areas in the fort that reflect its late 19th century use. Later adaptations for rooftop guns reflect the changing nature of conflict through the 20th century. Research has also revealed that the fort contains one of the best preserved of the rare Brennan torpedo installations, including the remains of a unique rising observation tower.