Sielecki Castle is the most striking building in Sosnowiec — a 17th-century fortified residence that has been converted into a regional art and culture center. The building sits on a low rise in the Sielec district, its pale walls and corner towers visible from the surrounding streets. Inside, the rooms host temporary exhibitions of contemporary and historical Polish art, and the courtyard is used for outdoor events in summer.
The castle is not a grand aristocratic palace but a solid, well-proportioned manor of considerable character. The grounds include a small English-style park with mature trees. It's worth an hour for anyone interested in Polish heritage architecture, and the exhibitions are often more interesting than what passes for contemporary art in larger cities.