On Ascot Heath in the middle of the racecourse. On a slightly raised plot of ground just outside the South East corner of the cricket ground, on the North side of the road to the pavilion.
SEALED Both shafts have been reduced to ground level. The access shaft has been capped with concrete and the ventilation shaft filled with rubble with the bent over reinforcing rods still visible. The monitoring room still exists below ground.
Opened in 1962 and closed in 1968.