Internationally, the Royal Gunpowder Mills is amongst a handful of places associated with the manufacture of explosives dating back many centuries which have subsequently been preserved and opened to the public. Gunpowder production began on the site in the 1660s and after the Crown acquired it in 1787 it became one of the world’s most important centres for the understanding and manufacture of gunpowder. A century later most of the factory was converted for the manufacture of chemical explosives and set standards that were emulated at home and abroad. Explosives manufacture ceased during the Second World War and after 1945 the site became the country’s most important explosives research centre until its closure in 1991.

The earliest water-powered mills were located along Millhead Stream. The site extends northwards for 38 hectares to embrace one of the largest scheduled industrial monuments in the country.

Unique remains include oval-shaped brick blast protection walls, built during the Napoleonic Wars at the beginning of the 19th century. The remains of cordite production dominate the area, including two nitroglycerine works and rows of guncotton drying stoves. The earliest listed buildings on the site date from the 1780s when the Crown first acquired the site.

Although utilitarian structures, they are fine examples of military buildings of this date. A long range of Victorian steam-powered gunpowder mills, built between 1861 and 1889, dominates the southern part of the site. Internationally, these are the most architecturally distinguished gunpowder mills. One is designated at Grade 1 and all but one of the remainder are listed at Grade II*. Nationally, only about 8% of all listed buildings are protected at these higher grades.

The Royal Gunpowder Mills carries a story which includes experimentation, industrial production, dangerous materials, risk, secrecy, security and the demands of war. It was for hundreds of years a nationally important, high tech, high security manufacturing and research facility which supported the British military machine from gunpowder through to the Blue Streak missile.

The development and production of ever more powerful explosives was just as much an ‘arms race’ in earlier centuries as that to develop the atomic bomb in the 20th century, with cutting edge of technology, using the latest power sources to operate the equipment.

Because of its secrecy and the physical isolation caused by its location, the site was self-contained, with its own power station, railway, road and canal systems.

It was a huge employer, drawing people into the area for work, expanding the town. During WWl the workforce numbered 6,000, about half being women. What they shared was the rule of secrecy, and today, local families can list members who worked here but not what
they did.

The site contains extraordinary buildings and structures, and can be enjoyed simply as a fascinating 'lost world' of buildings set within woodland, itself a product of trees first planted to make charcoal for the manufacture of gunpowder.