In a rectangular compound 50 yards east of an un-named minor road close to a disused telegraph pole.
LOCKED All surface features remain intact with some flaking of the light green paint. A metal dome and aerial bracket on the ventilation shaft indicates that this was a master post. The hatch is locked. This was one of 6 posts containing seismograph equipment (the others being Barham (Kent), South Creake (Norfolk), Lampeter (Cardiganshire), Llanuwchllyn (Merionethshire) and Middlemoor (Yorkshire). When questioned about these seismic stations in 1994 the public relations officer at AWE Aldermaston said “These form a part of the Ministry of Defense network of seismic stations used in connection with nuclear test ban verification. We have 6 seismic stations at former ROC sites. The use of the present tense would suggest that these stations were still operational. When inspected in 1994 the post at Barham was empty and open although it is now locked. When the South Creake Post was inspected in 1998 the seismic equipment and batteries were still there and operating. The equipment is looked after by a former post observer. It is unclear whether the equipment still remains in place at St. Breward.
Opened in 1960 and closed in 1991.