Leper window

A leper window was a window built low in the chancel wall of some medieval churches. It was usually iron barred and shuttered. Lepers stood outside and watched Mass through this window.

 References 
 Broderick, R. C. The Catholic Concise Encyclopedia. 1952. Simon & Schuster. p. 222. 
 Dictionary: Leper window

Category:Church architecture
Category:Windows (architecture)