The intersection is surmounted by a mighty octagonal tower. The main gate is framed by the two massive and unequal  western towers. Since its foundation by Charlemagne, the Cathedral has been the religous centre of the bishoperic Osnarbrück for more than 1125 years. The current architectural look dates back mainly to the late Romanesque periode in the 13th century.  The history of Osnabrück - a diocesan city - was played out around this Romanesque columned basilica at the "Große Domsfreiheit" (Market Square beside the Cathedral). The new Cathedral Museum includes sacred objects of interest and church treasures, including the triumphal cross (1180), the font (1225), the 12th century cloister and the high altar (around 1900).