About the castle does not mention medieval messages, which makes much more difficult to verify the view that it was erected on the initiative of king Casimir the Great in the 14th century and served as the watchtower of the western border of the Kingdom of Poland. According to archaeological research from 2000-2003, it is supposed that the castle was erected at the beginning of the 14th century, probably at the initiative of Jan Muskata, the bishop and starost of Cracow. Lack of later cultural layers would allow us to assume that it could not be completed or was used very briefly. It is not inconceivable that it served as a prison for nobles and all information about castle was kept secret; or it was the seat of knights-robbers. It is not known in what circumstances and when the castle was destroyed.
The castle consisted of two parts. On the rock, not accessible from the north and east, was the upper castle, which wall was marked by an elongated polygon with an area of 1200 m2 finished on the eastern side with bend. Inside you can see the remains of the building on a rectangular plan with dimensions of 10×30 meters, adjacent to the north-west part of the perimeter wall. To the southern section of the perimeter, a tower on a rectangular plan of 6×9 meters adjoined from the outside. It is not known whether it served as gatehouse or whether the entry was carried from the west. The lower castle was separated by a deep moat and was surrounded by a system of earth reinforcements.
Until today, only the foundations of the perimeter wall, the residential building and the gates tower with a height not exceeding one meter, have survived at the edges of the rock. The surrounding subterranean earth ramparts are also visible. In the rock on which the stronghold was erected, there is the Ostrężnicka Cave with corridors about 90 meters long.
Leksykon zamków w Polsce, red. L.Kajzer, Warszawa 2003.
Sypek R., Zamki i obiekty warowne Jury Krakowsko-Częstochowskiej, Warszawa 2003.