The Rialto Bridge is the oldest of the four bridges spanning the Grand Canal in Venice, Italy. Connecting the sestieri of San Marco and San Polo, it has been rebuilt several times since its first construction as a pontoon bridge in 1173, and is now a significant tourist attraction in the city. The present stone bridge is a single span designed by Antonio da Ponte. Construction began in 1588 and was completed in 1591. It is similar to the wooden bridge it succeeded.