The passage above the canal, linking the two buildings, is known as “The Bridge of Sighs”. It was used to relocate criminals to prison after their convictions in the courts of the Doges’ Palace. The bridge gets its name from the mournful sighs of the prisoners as they went to meet their inevitably unhappy fates.
Prisoners awaiting the transfer were kept in cells like these, although the cells weren’t so clean and well-lit at the time. They probably smell a lot better now, too.
I took this picture from within the Bridge of Sighs itself, looking down at the happy crowd of tourists and photographers who were there to unknowingly witness my walk into the darkness. All I needed to make it complete was for Septa Unella from Game of Thrones to follow me, ringing a bell and repeating the word “Shame” every few minutes.
(Why, yes, I do, occasionally, get a bit carried away with self-dramatization.)