Biblioteca Nazionale Marciana
There's a wondrous collection of centuries-old books and illuminated manuscripts at this library, located across the piazzetta from Palazzo Ducale in two buildings designed by Renaissance architect Sansovino, Libreria Sansoviniana (Sansovinian Library) and the adjacent Zecca (Mint). The complex was begun in 1537, and the Zecca was finished in 1545. Facing the Bacino (San Marco basin), the Zecca along with the Palazzo Ducale form Venice's front door. The Palazzo Ducale, built during a period of Venetian ascendance and self-confident power, is light and decidedly unmenacing. The Zecca, built in a time when the Republic had received some serious defeats and was economically strapped, is purposefully heavy and stresses a fictitious connection with the classical world. The library is, again, much more graceful and was finished according to Sansovino's design only after his death. Palladio was so impressed by the Biblioteca that he called it "beyond envy."
The books can only be viewed by written request and are primarily the domain of scholars. But the Monumental Rooms in the Sansoviniana are worth visiting for the works of Veronese, Tintoretto, and Titian that decorate its walls. You reach the Monumental Rooms, which often host special exhibits, through the Museo Correr.