The Castle of Arnóia is a medieval castle in civil parish of Arnóia, municipality of Celorico de Basto, the district of Braga. It was built in the late 11th or early 12th century, probably to defend the local monastery. The abandonment occurred from 1717, when elites left the small village of Basto, moving the seat of the county to the parish of Britelo, where today is located Celorico de Basto.
Today there are four defensive elements survived: the watchtower (whose rooftop and set of battlements were reconstructed in the 20th century), the quadrangular tower, a single door and the tank.
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.