RAF Menwith Hill

RAF Menwith Hill is a Royal Air Force station located near Harrogate, North Yorkshire, England. Constructed between 1956 and 1959, it became operational in June 1959. The base is owned by the Ministry of Defence but is made available to the US Department of Defense under the NATO Status of Forces Agreement 1951. It serves as a communications and intelligence support facility for both the United Kingdom and the United States, described as a communications intercept and missile warning site. The site is also known for its extensive satellite ground station, featuring numerous distinctive white radomes, locally referred to as "golf balls." It is alleged to be an element of the ECHELON system.

Initially named Field Station 8613, the site was first operated by the United States Army Security Agency (USASA). Control was transferred to the US National Security Agency (NSA) on August 1, 1966, due to advancements in digital technology and satellite intelligence. The station was officially renamed RAF Menwith Hill on February 19, 1996. Current operators include the Royal Air Force, United States Air Force, Government Communications Headquarters (GCHQ), and the National Security Agency. The US Air Force's 421st Air Base Squadron provides base and mission support services, while the US Army's 709th Military Intelligence Battalion also maintains a presence. The site covers 605 acres (245 ha) and continues to expand, with planning permission granted in 2019 for three new radomes, bringing the total to thirty-seven. Security is provided by the Ministry of Defence Police. As of November 2017, the station had 1,205 personnel, comprising US military, US contractors, US civilians, UK military, UK contractors, and UK civilians, including GCHQ staff.