Peterborough is a cathedral city and unitary authority area in the East of England, it is in the county of Cambridgeshire, The Town Hall is 75 miles (121 km) north of London at Charing Cross, The city is situated on the River Nene, which flows into the North Sea approximately 30 miles (48 km) to the north-east, The local topography is notoriously flat and low-lying, and in some places lies below sea level, The area known as the Fens falls to the east of Peterborough.