Excavations and built heritage recording on the site of the London 2012 Olympic and Paralympic Games have revealed evidence dating from the last Ice Age up to the modern period. Extensive geoarchaeological and palaeo-environmenal studies, coupled with a comprehensive radiocarbon dating programme, have enabled the valley's past environments to be reconstructed. As well as significant Neolithic finds, the excavations revealed Bronze Age and Iron Age settlements, and some evidence for Roman, Saxon and medieval activity. Aspects of post-medieval industry are examined, as are features relating to Victorian infrastructure developments and the rapid industrialisation of the lower Lea Valley.