Scanned from a photo postcard from 1924
The dungeons at the Chateau de Chillon located in an island in Lake Geneva, Switzerland.
The Chateau is known from Lord Byron's poem "The prisoner of Chillon" written in 1816, this was based on the exploits of François Bonivard (1493–1570) who was imprisoned in the dungeon.
Photo and published by Th. Anderegg of Chillon, Switzerland