On the building in the background of the Return of the Ambassadors by
Carpaccio there are two plaques - the subject on the one on the right
is The Forge of Vulcan. Can anyone please tell me what the subject
is of the plaque on the left?

The painting is in the Accademia, Venice, and is part of the St.
Ursula cycle. I am a PhD student of the University of Central
England researching the depiction of Vulcan in Renaissance Art. I
need to find out the subject of the second panel on the building in
the painting in order to see how it relates to the Forge of Vulcan on
the right hand panel.

Many thanks. A. Johnson