Battle of Britain House, also known over time as Franklin House and Kokyo, was a private mansion in Ruislip that was used by the United States military to train agents for undercover missions in occupied France during the Second World War. After the war, the house was dedicated as a memorial to the Royal Air Force squadrons involved in the Battle of Britain, and became a residential college and headquarters to the Ruislip & District Natural History Society. The house was destroyed by fire in 1984 and demolished; in 1993 the site was cleared to allow it to be reclaimed by nature.