On 6 July 2005, the day when London discovered that it had won the race to host the 2012 Olympic Games, the proposed Olympic Park was a brownfield, urban landscape in the Lea Valley. It comprised 321 hectares of light industry, disused workshops, some houses and allotments, partitioned by canals, roads, railway tracks with 52 pylons carrying power lines across the site. But it was not always like this. East London's Iron Age population would have lived in a valley of lakes and rivers and fished in today's River Lea. Archaeologists from the Museum of London have found that the Olympic Park bordered Neolithic and Bronze Age wetlands. In their evaluation trenches they found Mesolithic flints and Bronze Age crannogs, dwellings on piles driven into the wetlands. On the Aquatic Centre site, four prehistoric skeletons, one thought to be 3,000 years old, were discovered in separate graves in an area of an Iron Age settlement. In the third century AD, when the Olympic Games were being held in Ancient Greece, Romans or Romano British lived on the site, which shown by a coin with the Emperor Constantine II (337-340AD) on one side and Caesar on the reverse. K There was textile printing in the 17th century; later petrol factories, and bone, varnish, soap and tallow works, distilleries, engineering and chemical plants. From the end of the 19th century it was used for landfill. It has strong electronic associations too - in 1904 Professor Ambrose Fleming developed the first diode valve; Britain's first radio valve factory was established there in 1916, and the first television tube factory in 1936.