The Triangular Lodge is a folly, designed and constructed between 1593 and 1597 by Sir Thomas Tresham near Rushton, Northamptonshire, England. It is now in the care of English Heritage. The stone used for the construction was alternating bands of dark and light limestone.
Tresham was a Roman Catholic and was imprisoned for a total of fifteen years in the late 16th century for refusing to become a Protestant. On his release in 1593, he designed the Lodge as a protestation of his faith. His belief in the Holy Trinity is represented everywhere in the Lodge by the number three: it has three walls 33 feet long, each with three triangular windows and surmounted by three gargoyles. The building has three floors, upon a basement, and a triangular chimney.