Hidden in the hills to the east of Loch Long in Argyll and Bute is DM Glen Douglas, Europe's largest armaments depot which stores ammunition, weapons and explosives for the nearby HM Naval Base Clyde and also arms surface ships via a jetty at Glenmallan. In addition, it stores general munitions and bombs for the airforce and army, totalling around 40,000 cubic metres (1.4 million cubic feet) of capacity. Built in 1966, this isolated high-security facility comprises 56 storage bunkers built into the hillside, together with weapons processing and engineering workshops spread over a 263 ha (650 acre) site. Employing around 120 people, DM Glen Douglas is supplied by sea and by rail, via the West Highland Line, but also maintains a fleet of lorries that transport munitions across the UK. A new road-rail transfer facility was completed in 2016.
During the Cold War this was designated as a NATO depot, used by the UK, USA and the Netherlands. Following the withdrawal of US munitions in 1993, spare capacity was used by the Royal Air Force. Renamed as a Defence Munitions centre in 1994, it was previously classified as a Royal Navy Armaments Depot, known as RNAD Glen Douglas. DM Glen Douglas is now operated by Defence Equipment & Support, an executive agency of the Ministry of Defence.
