Story highlights Authorities say they discovered thousands of cannabis plants at various stages of growth

Bunker was built in the 1980s and meant to be used in case of a nuclear attack

(CNN) Police in the United Kingdom discovered a large cannabis factory after raiding a nuclear bunker on Thursday. The value of the crop they recovered was estimated at over £1 million ($1.2 million).

Police in the county of Wiltshire say they arrested six people during a midnight raid on RGHQ Chilmark, an underground nuclear bunker built in the 1980s to protect government officials and local dignitaries in case of a nuclear attack.

While the site is no longer owned by the UK's Ministry of Defense, the bunker is intact and the nuclear blast doors remain in place.

After receiving intelligence about the operation going on in the nearly impenetrable bunker, police said they waited outside for three people to leave and then detained them, using their keys to gain entry.

Inside, police said they found three more people, believed to be operating as gardeners along with several thousand cannabis plants at various stages of growth.

Read More