ACE HIGH was an early warning system dating back to 1956. It was designed as a self-contained system providing early warning of attack and also trigger retaliation. The system extended from northern Norway to eastern Turkey.

The system became redundant in the 1980s and was abandoned in the early 1990s.

The station at Coldblow was located by a Second World War communications station on Coldblow Hill. It consisted of two pairs of parabolic dish antenna. The transmitters, receivers and power supplies were located in a single storey brick building between the pairs of dishes. When the Ace High network closed the Coldblow station was sold. The dishes had previously been removed. A microwave tower on the site was retained by the Ministry of Defence.. The mast is currently used by the USAF in conjunction with the USAF radio stations at Dunkirk and Swingate in Kent.

Most of the remaining buildings are unused and derelict. (1)

Formerly listed as TQ 85 NW 131, but was identified as a duplicate number and changed in November 2016

<1> Nick Catford & Andy Emmerson, 2004, Description of the Coldblow Ace High station on the Subterranea Britannica website (Website). SKE13301.