The stronghold became the seat of the administrator of the lands of the Warmian Chapter. The administrator ruled over a third part of Warmia, including cities such as Frombork, Pieniężno and, of course, Olsztyn. The chapter's granary and treasury were located here. Primarily, however, the castle had defensive functions.

Of course, as the centuries passed, the castle lost its defensive importance. It was also rebuilt several times. Today, the building consists of two Gothic wings connected by a curtain wall and a late Baroque part, through which there is an entrance to the courtyard. We will find there, among others: stone statue of the so-called Prussian woman brought from Barciany. Little is known about its origin and function. Similar statues were found in the lands formerly inhabited by Prussian tribes, conquered by the Teutonic Knights in the 13th century. There is also a Versailles boundary stone from 1919, as well as a closed well.