Guildford is the county town of Surrey. England, as well as the seat for the borough of Guildford and the administrative headquarters of the South East England region. It is situated 27 miles (43 km) southwest of London on the A3 trunk road linking the capital to Portsmouth. The town has Saxon roots and likely owes its location to the existence of a gap in the North Downs where the River Wey is forded by the Harrow Way. The town grew enough in importance that by 978 it was home to the Royal Mint. With the building of the Wey Navigation and Basingstoke Canal Guildford was in the centre of a network of waterways that aided its prosperity.