"a house with the picture of a camel raised in relief"

Camel detail on house
Creative Commons AttributionCamel detail on house - Credit: justclaire
The camel adorns the Palazzo Mostello, home of the Mori brothers from Morea in the Peloponnese (no.11 on the map at the back of the book: Afterwordp.7). 

A more prosaic explanation for the camel is that the brothers made their money trading in spices from the East.