Lubcha Castle was a residential castle of the Radziwill family on the left bank of the Neman River at Lubcha near Navahradak. The castle was founded in 1581 as a fortified residence of Jan Kiszka, a powerful Calvinist magnate. It had timber walls, a single stone tower, and was surrounded by moats on three sides, the fourth side protected by the river. Lubcha later passed to Janusz Radziwiłł, Great Hetman of Lithuania, who expanded the castle by adding three stone towers. In 1655 it was taken and devastated by the rebellious Cossacks under Ivan Zolotarenko.
Only the barbican and one other tower were left standing after the Cossack incursion. The deserted estate changed owners several times, remaining untenanted until the mid-19th century, when a Gothic Revival palace was built on the grounds. The Lubcha estate suffered much damage during both world wars. The palace was reduced to a shell in 1914 and was remodeled into a school building by the Soviets in 1947.
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.