A three hour walk along the Lea Valley, starting from Three Mills and ending at St. James Street.
Points of interest on the route include The Greenway (Olympic Park viewpoint), River Lea Navigation, Old Ford Lock Keeper's Cottages, Middlesex Filter Beds, Lea Bridge Sluices, Walthamstow Marshes, and Coppermill Lane (Thames Water Resevoirs).
AVRO Aircaft event on Walthamstow Marshes (from 1pm to 4pm).