The Castle of Trezzo sull'Adda is located on a hill within a bend of the Adda river and from this protected on two sides. On the remaining side it is closed by a wall and a 42-meter high tower. Part of the castle was the fortified bridge over the river, destroyed in 1416.
The site was inhabited since prehistoric time by Celtic populations and after the VII century hosted a Longobard settlement, which was also at the origin of the first fortification on the hill. In 1370 Bernabò Visconti, lord of Milan, ordered the construction of a new caste, which was built on the remains of the previous fortress and completed in 1377.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.