The Rialto Bridge is one of the four bridges spanning the Grand Canal in Venice, Italy. It is the oldest bridge across the canal. The present stone bridge, a single span designed by Antonio da Ponte, was completed in 1591 and was used to replace a wooden bridge that collapsed in 1524. The engineering of the bridge was considered so audacious that some architects predicted a future collapse. The bridge has defied its critics to become one of the architectural icons of Venice.