'Criggion Radio' was a transmitter site latterly operated by BT on behalf of the UK Ministry of Defence. It was located near the village of Criggion
in the parish of Bausley with Criggion
, which lies in the county of Powys
. Criggion Radio was established in World War II
as a back-up unit for the Rugby VLF transmitter
and took over the latter's traffic for a short period in 1943 following a fire at Rugby. Operating on 19.6kHz with the callsign GBZ, the Criggion VLF transmitter was used until its shutdown on April 1 2003
for sending messages to submarines. This task (and that of Rugby) is now carried out by the Anthorn VLF transmitter
. Criggion's VLF antenna was hung from three free-standing steel framework towers (height 182.9 metres), two guyed masts (height: 213.4 metres) and a rock anchor.
The towers and masts were demolished in August 2003 and there is now no visible evidence that a large radio station ever existed on the site.