San Polo is the smallest of Venice's sestieri, but it contains the Rialto — the commercial heart of the city since the medieval period — and the Frari, the great Gothic basilica that holds the greatest concentration of major paintings in any church in Venice. It is also home to the Scuola Grande di San Rocco with its Tintoretto cycle.
The streets around Campo San Polo are quieter than those near the Rialto and good for aimless walking. The campo itself is one of Venice's larger open spaces and hosts outdoor cinema screenings in summer. The market at Rialto — the fish market on the canal side, the produce market on the other — is best seen early in the morning before the tourist crowds arrive. This is also the most concentrated area for bacari, the small Venetian wine bars where you stand at the counter and eat cicchetti (small snacks) before lunch or dinner.