The Castello Visconteo di Pagazzano is a moated, late-medieval castle which originates from the 11th century. It was burned down and 200 inhabitants were killed in a battle in 1353. The castle and the territory of Gera d’Adda, including Pagazzano, was inherited in 1354 by Bernabò Visconti. The territory was disputed over the centuries by surrounding ruling forces, and various Visconti descendants. In the 19th century, the castle was owned by the Crivelli family until 1968 when it was bought by a private initiative, and sold to the Comune di Pagazzano in the year 2000.
The structure has been built with bricks and is rectangular in shape. The southern part has lost the towers at the south-east and south-west corners. In 1553 Galeazzo Visconti ordered the integration of the mansion into the castle. The drawbridge still exists and is used as pedestrian passage, the castle is also surrounded by a moat full of water. The drawbridge is on the northern side and is about 4 metres long, it still works today. The main entrance is also here, situated in the majestic central tower. The defensive use of this central tower depended on a system of battlements. Along the walls there is a look out tower where a bell rang, so the people could take refuge inside the walls in case of danger. The oldest part includes huge rooms and the dungeons.
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.