The castle of Trezzo, situated on a bluff on a bend of the Adda River and protected on both sides, on the third side was a square Tower 42 meters high.
The castles of the Visconti in Milan era form a sort of a belt around the constellation of Orion. This location makes them easily accessible through a continuous path that allows you to highlight the main stylistic-structural characters and the most common types.
The castle of Trezzo, one of the most important of the milanese, was built to protect the bridge and because of its strategic location was initially contested by Frederick Barbarossa and the city of Milan and later between the Visconti and the Torriani. It was repeatedly destroyed or burned but always rebuilt.
The remains are those of the construction of the 1370 by Bernabò Visconti which was the residence and then jail until his death (1385) at the hands of his nephew Gian Galeazzo Visconti. The bridge was single span of 72 meters high, 25 meters above the water surface, fortified and built on three levels for the separate step of carts and pedestrians; for the times was a remarkable feat of engineering.
The castle was captured by Paolo Colleoni, father of Bartolomeo Colleoni and with relatives on 23 October 1404 and from those held as a base for incursions into the territory until the reconquest of Carmagnola which was demolished. From that moment began the decline of the Castle used, among other things, in the 19th century for building material for the Arena in Milan.
In Concesa there is the sanctuary of the divine motherhood of Mary. It was built in 1641 by Cardinal Cesare Monti and assigned to the order of the Discalced Carmelites of St. Teresa. Designers of the monastery were the engineers Francesco Maria Richini and Carlo Buzzi (both committed to Veneranda Fabbrica del Duomo di Milano).
Villa Gina, as the castle is built on a spur overlooking the Adda River. It was built in the 16th century on a previous Concesa fortified building and was restored in 1855 following the dictates of eclecticism. The sloping terraced gardens on the river and on Chile of the Martesana Canal. The villa is presently owned by the city of Trezzo and headquarters of the North Adda Park.