Roman technology made its impact in road building and the construction of villas, forts and cities. During their occupation of Britain the Romans built an extensive network of roads. They were used in later centuries, and many are still followed today. The Romans also built water supply, sanitation and sewage systems. Many of Britain's major cities, such as London ("Londinium"), Manchester ("Mamucium") and York ("Eboracum"), were founded by the Romans.