Ancestral castle was built Radziwills Nicholas Radziwill " Black " in 1558 It was one of the first to square bastion locks. Its area was 2.7 hectares , in the palace , there were 365 rooms, as well as days in the year . Over the years 1591-1648 . Olyksky castle withstood many sieges , but was captured only once - by the Swedes in 1702 By the end of the XVIII century. he lost his defensive value , but until the middle of the XX century. remained the residence of Radziwill . In 1737-1755 years. Michael Casimir "Fish" Radziwill rehabilitated . Appeared on the territory of three-storey palace, north- west gate decorated bunk clock tower . The last owner of the castle was Janusz Radziwill, who was arrested in 1939 and spent several years in Stalin's camps . In Soviet times on the castle grounds put regional psychiatric hospital number 2, which occupies premises now. Free entrance to the courtyard .