Remote Radar Head Brizlee Wood (RRH Brizlee Wood) is an air defence radar station operated by the Royal Air Force near Alnwick in Northumberland, England. The site was originally established in the early 1960s as one of the Ace High sites, a NATO communication system, and was equipped with four 40-meter dishes operated by the Royal Signals. The Ace High network was superseded in November 1990, leading to the site's closure in early 1991. Subsequently, the site was converted into an RAF radar facility, initially equipped with a Type 93 radar. It now forms part of the Air Surveillance and Control System (ASACS) of the Royal Air Force, feeding information into the Control and Reporting Centre (CRC) at RAF Boulmer. The facility houses a TPS-77 radar within a single radome. The site underwent an upgrade in 2020 under Project Hydra and is slated for further technological upgrades as part of Project Guardian, an £80 million air defence program.