Chilmark, Wiltshire

Chilmark stone, a form of limestone, was quarried here and used for buildings including Salisbury Cathedral. Stone extraction continued on a small scale until the quarry closed c. 2007. Similar stone is still mined at Chicksgrove Quarry, 1.3 miles (2.1 km) to the southwest.[9] The former quarries have been designated as a Site of Special Scientific Interest (biological and geological), and as a European Special Area of Conservation for their bat population.

In 1936 the quarries, and land extending further down the ravine, were bought by the Air Ministry and the site became RAF Chilmark, which was the home of No. 11 Maintenance Unit RAF.[5] Munitions were stored in the quarry caverns, and for a time the unit had extensive above-ground storage areas in woodland near Dinton and in Grovely Wood.

A spur left the London-Exeter railway west of Dinton station at Ham Cross, just east of the bridge over the Chicksgrove-Fovant road, and entered the foot of the ravine; this spur was omitted from Ordnance Survey maps.[10][11] Goods were transhipped under cover of a large shed, to/from a 2 ft gauge narrow-gauge railway which ran into the ravine and some of the former quarry caverns.[12] Until c.1951, sidings at Wylye station on the Salisbury–Westbury line provided transport for the Grovely Wood area.[13]

By 1965, Chilmark was the RAF's only ammunition supply depot.[14] RAF Chilmark closed on 27 January 1995,[15] although clearance of explosives from the site continued until at least 1997.[16] A 1939 diesel locomotive used at the site was bought in 1976 by the Bala Lake Railway, North Wales;[17] several wagons are at the Old Kiln Light Railway, Surrey.[18]

Former RAF Headquarters

A Planning Brief prepared by Salisbury District Council in 1999 concluded that options for re-use of the site, except for the former headquarters buildings, were limited owing to the presence of bat colonies and the possibility of contamination remaining from the storage of munitions.[19]

Until 2015, the former RAF headquarters and some 55 acres (0.22 km²) of land in and near the ravine were used by a private company as a training area for counter-terrorism security and explosives handling.[20]

An underground bunker was built in the ravine in 1985, ready to act as the Regional Government Headquarters (RGHQ) for the southwest region in the event of a nuclear attack. It ceased to be operational in 1992, following the end of the Cold War, and was sold in 1997.[21][22]

During the night of 22 February 2017, officers from Wiltshire Police raided the bunker following information received that it had been converted for use as a cannabis farm. There are approximately 20 rooms in the building, split over two floors, each 200 feet long and 70 feet wide. Almost every room had been converted for the wholesale production of cannabis plants, and there was a large amount of evidence of previous crops. The farm was estimated to be able to produce £2m worth of cannabis per year using £250,000 worth of stolen electricity, with a crop of 4,000 plants every six weeks. The lighting equipment alone was estimated to have cost about £140,000. Three men admitted conspiracy to produce class B drugs and abstracting electricity. Charges of conspiracy to hold persons in slavery or servitude were initially made, but dropped due to lack of evidence.[23] It took ten days to search and clear the site, which was said to be the biggest cannabis factory found in the southwest region.[24] Custodial sentences were imposed on the three men in August 2017.[25]