If we want to summarise the magnificence of Venice with some numbers, here are some figures for you:
1 square: the only one named after Saint Mark, as all other urban spaces are called campi or campielli.
102 campi: the campo (field) is always located next to an important public or religious building. As many of the campielli it is often centered by one or more wells.
148 bridges connecting 124 isles, surrounded by 178 canals.