In the previous image I mentioned the Punta Alla Dogana which sits on a spit of land which forms the southern bank of the entrance to the Grand Canal. This church, the Basilica di Santa Maria della Salute (Saint Mary of good health) lies just to the west on the same spit.

The church has a distinctive octagonal shape and dates back to a massive plague outbreak which hit Venice in 1631. It wiped out about a third of the population but oddly, displays of the sacrament, prayers and processions failed to stem it. As an offering of thanks to a loving god for not wiping out the other 2/3rds of the population (yet), it was decided to build some grand monuments to said deity. This was one of them. It's made of Istrian stone (a form of limestone from Istria, a peninsula that juts out into the northern Adriatic) and marble coated brick.

It's a dual dome design with two belltowers, and is regarded (rightly in my view) as being one of the main emblems of Venice.