Chilworth Gunpowder Works was one of the largest, most prestigious and longest-lived powder mills in the country. Established by the East India Company in 1625, it was worked by a string private companies and became one of the most significant suppliers of gunpowder to the Government. In 1885, a consortium which included leading German powder manufacturers acquired the works to produce a new type of gunpowder known as 'brown' or 'cocoa' powder, for use in the largest guns of the day. By the end of the 1880s, and after extensive rebuilding, contemporary commentators regarded the factory as being of international standing. The most up to date machinery was imported from Germany, and to preserve the company's manufacturing secrets the new factory was managed by a former Prussian officer, Captain Otto Bouvier, and a number of German foremen. The company was also at the forefront of the development of new chemical propellants and in 1892 it erected the first commercial cordite factory in the country. It underwent further expansion during the First World War, but the massive downturn in the demand for explosives at the end of the war resulted in the closure of the factory in 1920. Subsequently many of the factory buildings were converted into dwellings, and a small community known as 'Tin Town' lived in the valley until the early 1960s. The archaeological remains of the works are of great significance, because the layout of almost the whole factory can be understood careful analysis of its earthworks, watercourses, ruins and standing buildings. This may imply that there is good potential for the survival of buried archaeological deposits relating to the early use of the site. Because of the international standing of the factory, some of the buildings, like the powder mills built in the 1880s, are surprisingly ornate, and therefore important in their own right. As a result, English Heritage has decided to give the area legal protection as a Scheduled Ancient Monument. The land owned by Guildford Borough Council is also important to the local community as a wildlife haven, and to ramblers and dog-owners as a pleasant place to walk.