The site was originally that of the Middlesex County Asylum at Hanwell. It was the first Asylum built in England under the 1808 County Asylums Act, opening in 1831 to provide for the pauper insane. At one point, it was the largest asylum in the world. It has undergone several changes of name during its history, but psychiatric work still continues to this day. During the 1980's, the hospital was reduced in size and part of the grounds sold off. The remaining area is part of the headquarters of the West London Mental Health (NHS) Trust.
This photo shows where the old entrance from the canal was before it was bricked up and the towpath leveled out. Coal was taken into the hospital for its furnaces, and excess vegetables from the garden were taken out.