Sheffield is the most geographically diverse city in England^[1]. The city nestles in a natural amphitheatre created by a number of hills and the confluence of five rivers: Don, Sheaf, Rivelin, Loxley and Porter. As such, much of the city is built on hillsides, with views into the city centre or out to the countryside. The city is roughly one third urban, one third rural and one third in the Peak District. At its lowest point the city stands just 29 metres above sea level at Blackburn Meadows on the Rotherham border, rising up to over 500 m in some parts of the city to a peak of 548m at High Stones on the Derbyshire border; however, 89% of the housing in the city is between 100 and 200 metres above sea level.