The Rzeszów castle is undoubtedly one of the most interesting monuments of the city - not only because of its history, but also because of the fact that it is an interesting testimony to conservation thought from the turn of the 19th and 20th centuries, when its present form was created.
The castle was located south of the city, in the village of Staroniwa, at the end of an elongated loess headland surrounded on three sides by water obstacles: the Wisłok River and ponds or swamps. The intersection of this promontory with a moat substantially strengthened the defense of this place. In this area, during archaeological research, traces of prehistoric settlement (in the area of the northern curtain of the bastion fortifications) and late-medieval (on the southeast bastion) were found. At present, the hypothesis about the existence of a defensive court, mentioned in the document from 1447, regarding the division of property between Jan and Stanisław Rzeszowski is unlikely to be verified, but this hypothesis is very likely.
http://www.rzeszow.pl/miasto-rzeszow/historia/zabytki-rzeszowa/zamek-w-rzeszowie