Sheffield, with a population of approximately 556,500, is the largest City in South Yorkshire and the fourth largest by population in England. The City enjoys good communications lying adjacent to the M1 motorway and also the M18, which links Sheffield to East Yorkshire and Lincolnshire, and benefits from good national and local rail links. Historically the economy was associated with steel production and engineering and whilst these are still large employers within the City today and indeed expanding sectors once again, the economy is much more diverse with finance, hi-tech industries, construction, Government and the service sector all being large employers. Sheffield now promotes itself as a green City with over 60% of its land mass being green space and with the Peak District National Park on the doorstep.