There are many dungeons in Old Jerusalem! There are many of them here from different eras, sizes, purposes. People spent years studying them, but I was only for a week in Jerusalem. Here I will give only a brief superficial overview of the subject, without diving into the history and without touching on the intricacies. Moreover, the topic is extremely sensitive, because it concerns the deep religious feelings of different faiths.
The photo shows the entrance to the tunnels of the Western Wall. On the right is the actual descent into the tunnels, where there is a man with a backpack - there is a ticket office and military police post. You can get here from the area of the Western Wall. The photo shows the tunnel itself under the houses of the Muslim Quarter.