[6] The Trezzo Bridge was built between 1370 and 1377 by order of the lord of Milan Bernabò Visconti.

[2] Fortified with towers, it provided access to the Visconti Castle high above the Adda.

[2] During a siege in 1416, the condottiero Carmagnola deliberately caused the structure to collapse by weakening one of its abutments.

[8] By comparison, the second largest pre-industrial bridge vault, the French Pont de Vieille-Brioude, spans 45 m (148 ft).

[9] Longer masonry arch spans were not achieved until the 1903 Adolphe Bridge in Luxembourg.