Only minor remnants of a stronghold, founded in the 14th century under the reign of the House of Berka of Dubé, have survived on the rocky hill between the Rákos and Kunz mines (not far from the Small Wolf Stream). The stronghold probably provided a refuge for glassmakers from the nearby glassworks. Archeological surveys have confirmed that both buildings come from the same period. At the end of the 14th century Vlčí hrádek (the Wolf's Castle) became desolated and we do not know the original name of the castle.