Located upon a steep slope above the San River, Sanok Castle was first built by King Casimir the Great after 1341 in the place of a wooden Ruthenian stronghold. Such was its splendour that the royal wedding of King Ladislaus II Jagiello and his third wife Elizabeth Granowska took place here in 1417. The medieval stronghold was further beautified into a Renaissance residence in the early 16th century, and expanded in the 17th and 18th centuries. During the Austro-Hungarian period all of the castle’s structures were demolished with the exception of the main building, the value of which was also diminished due to alterations, and during Nazi occupation the castle was thoroughly plundered. Works to restore the main building’s Renaissance appearance began in the 1990s, and in 2011 the reconstructed southern wing was opened. Medieval defensive walls have also been reconstructed and revitalisation works are ongoing.

Today Sanok Castle is the seat of the Sanok Historical Museum, with rich collections of Orthodox and Greek Catholic sacral art, Roman Catholic sacral art and Pokuttyan ceramics. The new wing hosts the museum’s biggest draw - the Gallery of Zdzisław Beksiński. One of PL's most internationally recognised 20th century painters, Zdzisław Beksiński (1925-2005) was born in Sanok and is famed for his large, almost luminous, and emotionally-charged canvases depicting grotesque figures and apocalyptic landscapes. The themes of war, ruin, decay and deformity are prevalent throughout his work, which has been described as both 'fantastical realism' and 'dystopian surrealism.' Featuring 600 works handpicked by the artist, Sanok possesses the most comprehensive collection of his work anywhere.