Housed in the Renaissance-style castle , the museum is best known for its 700-piece collection of Ruthenian icons. The selection consists of about 260 large pieces dating from the 15th to the 18th centuries, most acquired after WWII from abandoned Uniat churches. The museum’s other treasure is the collection of paintings by Zdzisław Beksiński (1929–2005) on the top floor. Beksiński, who was born in Sanok, was one of Poland’s most remarkable contemporary painters, with a fantastical style all his own.