Bath is a city in the west of England, in the county of Somerset on the River Avon, about 20 km from the larger city of Bristol. It is famous for its Roman baths, which were developed from warm springs by the Romans living here at the time, starting in AD 43. According to tradition, these were the only hot springs in England and were already known in pre-Roman times. From the time of Elizabeth I onwards, Bath increasingly developed into a spa town for the wealthy. As a result, the city still has many historic buildings, particularly from the Georgian era. The building stone that characterises the cityscape is Bath Stone, quarried in the surrounding area.