Guildford ( ())is the county town of Surrey, England. It lies 28 miles (45 km) southwest of London on the A3 trunk road between the capital and Portsmouth. As of the 2011 census, the town has a population of about 80,000 and is the seat of the wider Borough of Guildford which had an estimated 147,889 inhabitants in 2018. Due to recent development running north from Guildford, and linking to the Woking area, Guildford now officially forms the southwestern tip of the Greater London Built-up Area, as defined by the Office for National Statistics.