Royal Air Force Menwith Hill or more simply RAF Menwith Hill is a Royal Air Force station in England which provides communications and intelligence support services to the United Kingdom and the United States of America. The site contains an extensive satellite ground station and is a communications intercept and missile warning site and has been described as the largest electronic monitoring station in the world.
The Maunsell Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom.
The intense secrecy surrounding the base made it the frequent subject of conspiracy theories and a central component to unidentified flying object (UFO) folklore.