The Whitgift Almshouses (formerly The Hospital Of The Holy Trinity) were founded in 1596 by the Archbishop of Canterbury, John Whitgift, as a gift to the people of Croydon. They are a symbol of Croydon's former status, as the Archbishops had a palace in Croydon for their summer residence. The ruins became part of Old Palace school: http://www.oldpalace.croydon.sch.uk/history-of-the-school
