Okiennik Wielki is one of the better-known limestone forms in the Ogrodzieniec area, a high rock with a natural "window" cut through it. It sits north of town near Skarżyce, so it is more of a short excursion than a walk from the castle.
Climbers come for the routes on the rock faces, but casual visitors can just walk around the base and enjoy the odd shape of the Jura landscape. It is best paired with the castle if you have a car or are spending a full day in the area.