Hajciuniški Castle, Castle in Hajciunishki, Belarus

Hajciuniški Castle is a two-storey brick residence of 15 by 34 metres under a high hipped roof, built as a reduced castle. Four round corner towers with narrow loopholes and a three-storey central entrance tower flank the almost undecorated facades, whose walls are about 1.5 metres thick. Inside, a vestibule with two staircases leads to services and a small garrison barracks on the ground floor and to the owners' rooms and dining hall above.

Peter Nonhart, an engineer and head of royal buildings in Vilnius, built the fortified house in 1611–1612 with the fortification engineer Van Daden on the left bank of the Zhizhma. In the 17th century it passed from the Nonharts to Yuri Khreptovich, voivode of Novogrodek, then to his son Adam. Later owners included the painter Schröttter, the Putkamer and Osten-Sacken families, and the Rymshas from 1830. During the Northern War Swedes defended it against the troops of Augustus II.

The house-castle was built in 1611–1612 for Peter Nonhart, a Dutch engineer and Vilnius city captain, and his wife. In the 19th century the Rymsha family added a wide porch with a terrace, altering the original design. A 15-hectare park of lindens and larches, some over 300 years old, surrounded the estate.

The building now houses a republican psychiatric hospital for compulsory treatment, so interior access is not available to tourists. The structure stands on the left bank of the Zhizhma River at the southern edge of Hajciunishki; the 15-hectare park that once surrounded it, planted mainly with lindens and larches, has not survived. The ruins of the Nonhart family tomb, built in 1633 in the Baroque style, lie nearby, along with 19th- to early 20th-century outbuildings.

The corner and central towers rest on foundations that do not reach solid ground, unlike the main building's deep foundation. This stems from the cellars and high groundwater: only stone pillars set in lime mortar support them, and the main foundation projects about a metre beyond the walls.