Virtual Tour - strongrooms 

The top floor of the building contains the archive stores, fitted with around 12,500 metres of mobile shelving (enough for about 75,000 boxes), with strict controls for temperature, humidity, air circulation, fire prevention; and a very sensitive smoke detection system. There are also special rooms for the storage of audio-visual material which can be less stable and more delicate than paper documents - the controls in these parts of the strong rooms are correspondingly stricter.