 This would supply not only Longovicium but other nearby forts.However, the site is almost unique in Britain for the size of its water supply, and the remains imply large-scale iron smelting, perhaps assisted by watermills for forging iron products.Much of what we know about the site is due to the large number of altars, dedication slabs and a milestone dedicated to emperor Gordian III found half a mile away from the fort on the path of Dere Street.