Complex sentence: Situated on the river Trave, it was for several centuries the "capital" of the Hanseatic League ("Queen of the Hanse") and, because of its Brick Gothic architectural heritage, is listed by UNESCO as a World Heritage Site.
Split into simpler sentences: Situated on the river Trave, it was for several centuries the "capital" of the Hanseatic League ("Queen of the Hanse"). Because of its extensive Brick Gothic architecture, it is listed by UNESCO as a World Heritage Site.