The Lubomirski Castle is the largest secular building in the city — a vast pentagonal fortified residence built between 1591 and 1626 by Mikołaj Spytek Ligęza and remodelled in the Italian palazzo style by the Lubomirski family in the next century. Surrounded by ramparts and a now-grassy moat, it dominates the southern edge of the old town.
The castle was used as a prison from 1820 right through to 1981 — first under the Austrians, then the interwar Polish state, then the communist regime — and the conversion into a museum and venue for the Subcarpathian District Court is still ongoing. Parts of the interior can be visited, including the old prison wings, the courtyard, and seasonal exhibitions in the main halls. The grounds and the bastioned moat are freely open and worth a circuit.