[By James Hobbs in London] Hackney Marshes is one of London’s largest areas of common land, 340 acres that lie on the banks of the River Lea, a tributary of the Thames that runs through north and east London. The Marshes are a focus for a variety of amateur sports, but especially Sunday league football, and the scale is quite boggling. As I drew this, I could count 94 goalposts – as well as a handful of rugby posts – receding into the distance across the field around me. But that’s only part of it. There are more than 80 full-size pitches here in total, and to visit it on a Sunday, swarming with enthusiastic sportspeople on an industrial scale, is to see it in a very different light. A short walk away is the 2012 Olympic Park, the scene of great athletic, cycling and swimming moments, but the enthusiasm displayed by those who play at the Marshes is no less.