The view is along the Riva Degli Schiavoni looking west towards the San Marco and the campanile (the tower at the right) as well as Santa Maria della Salute (the domed building towards the left). The entrance to the Grand Canal is between these two structures.
In the painting, at the right, you can see the bridges which cross the various canals that lead into the lagoon. To me, it appears that Sargent is painting this from a rooftop of a church that is located (on the map) right above the letters "Sc" of "Schiavoni" (but I can't make out the name of the church).
From Philip ReshephSargent again painted along the Riva Degli Schiavoni but this time much closer to San Marco.
Cafe on the Riva degli Schiavoni
in Italy, 2002-2003
By: Natasha Wallace
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