he ruins of the duke's castle on the Æar Mountain. It was built by the dukes of O¶wiźcim in the mid-14th century. In 1477 Kazimierz Jagiellończyk had the castle enlarged. The structure was set on a stretched oval plan (20x50m). The defensive system was reinforced by a ditch (double on the northern side) and a rampart.

According to legend the last resident of the castle was burned for banditism. Some walls of the foundation as well as the basement and remnants of ramparts have survived up to now. The easiest way to get to the remains of the castle is to follow the blue route leading from the monastery in Kalwaria Zebrzydowska along the ridge of the mountain.