Peterborough is a cathedral city and unitary authority in the East of England, with a projected population of 161,800 as of 2007. For ceremonial purposes it is in the county of Cambridgeshire. The Town Hall is 75 miles (121 km) north from the centre 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. The City of Peterborough includes the outlying settlement at RAF Wittering, and as a unitary authority borders Northamptonshire and Rutland to the west, Lincolnshire to the north, and Cambridgeshire to the south and east. Human settlement in the area dates back to the Bronze Age, as can be seen at the Flag Fen archaeological site to the east of the current city centre. This site also shows evidence of Roman occupation. The Saxon period saw the establishment of an abbey, which later became Peterborough Cathedral. The population grew rapidly following the arrival of the railways in the nineteenth century, and Peterborough became an industrial centre, particularly noted for its brick manufacture. Following the Second World War growth was limited until designation as a New Town in the 1960s. The population is once again undergoing rapid expansion and a £1 billion regeneration of the city centre and immediately surrounding area is underway. In common with much of the UK, industrial employment has fallen, with new jobs tending to be in financial services and distribution.