San Polo is the smallest of Venice's six sestieri, a compact tangle of streets and canals centered on the Rialto, the commercial heart of the city for over a thousand years. The Ponte di Rialto, the oldest and most famous bridge crossing the Grand Canal, connects San Polo to San Marco and remains one of the most recognizable landmarks in Venice. Just steps from the bridge, the Rialto fish and produce markets (Pescheria and Erberia) have operated in the same location since the 14th century, and they continue to supply restaurants and households across the city each morning. The campo that gives the sestiere its name, Campo San Polo, is one of the largest open spaces in Venice, used for outdoor cinema screenings in summer and carnival events in winter. The monumental Basilica di Santa Maria Gloriosa dei Frari, known simply as "i Frari," houses masterworks by Titian and Bellini and rivals San Zanipolo as the most important church in Venice after the Basilica di San Marco. Nearby, the Scuola Grande di San Rocco contains Tintoretto's extraordinary cycle of more than sixty paintings, often called the "Sistine Chapel of Venice." San Polo packs an enormous amount of history, art, and daily Venetian commerce into a remarkably small area.