The San Marco Basin (Bacino di San Marco ) is, in Venice , the water space in front of Piazza San Marco , between the channels of the Lido , Giudecca and the Grand Canal : There is encircled by the quay of the Piazzetta (with amount of Palazzo Ducale , the columns of San Marco and San Todaro and the facades of the Marciana Library ), the Riva degli Schiavoni (with severe façade of Prisons ), the ' island of San Giorgio Maggiore (the basilica and monastery ) and The point of the Dogana , with his Golden Ball .