|— Comune —|
|Città di Trezzo sull'Adda|
|Frazioni||Cascina Figini, Concesa|
|• Mayor||Danilo Villa (since 2009-06-09)|
|• Total||12.8 km2 (4.9 sq mi)|
|Elevation||187 m (614 ft)|
|• Density||970/km2 ( 2,500/sq mi)|
|Time zone||CET (UTC+1)|
|• Summer (DST)||CEST (UTC+2)|
|Patron saint||San Gaetano|
The Naviglio Martesana canal starts from the Adda in Trezzo's territory.
Trezzo received the honorary title of city with a presidential decree on 8 July, 2008.
Main sights 
Trezzo's main attraction is the massive castle which belonged to the powerful Visconti family in the 14th century. Protected by the Adda on two sides, it had a 42 m-high square tower on the third one. Its fortified bridge (see Trezzo sull'Adda Bridge) was 72 m long, the longest bridge span for several centuries, built on three different levels, passing 25 meters over the waters.
Due to its strategic position, the castle was contested first by Emperor Frederick Barbarossa and Milan, in the 12th century, and later by the Visconti and the Torriani families. The castle was destroyed or burnt several times, but was rebuilt on each occasion. The last reconstruction dates from 1370. It was commissioned by Bernabò Visconti, who was later imprisoned there until his death.
On October 23, 1404, the castle was captured by Paolo Colleoni, father of the important condottiere Bartolomeo. The Visconti general Francesco Bussone recaptured it, partially demolishing it and starting its decline. In the 19th century it was used as a quarry for the construction of the Arena di Milano.
Another attraction is Villa Gina, a 17th century villa built on the Adda with fine terraced gardens. Today it is the seat of the Adda Nord Regional Park.
- Media related to Trezzo sull'Adda at Wikimedia Commons
- Official website
- Page about the castle (Italian)