Discover Rialto Bridge

The bridge is a single segmental stone arch of roughly 28.8 metres, rising about 7.5 metres above the water. A span of that width with no intermediate support was considered a serious gamble when it was proposed, and several of the period's leading architects submitted designs before Antonio da Ponte's was chosen.

Its structural problem was the ground rather than the arch: Venice's lagoon bed offers no bedrock. The abutments rest on some 6,000 timber piles driven into the silt on each bank, angled to spread the arch's outward thrust rather than merely carry weight downward.

The facing is Istrian stone, the dense limestone used throughout Venice for its resistance to salt water. Above the deck, twin arcades of shops flank a central portico, with wider stairways to either side -- an arrangement that lets the bridge carry commerce and pedestrian traffic on the same span without the two obstructing each other.