Frauenalb Monastery was founded in the late 12th century. It accepted as members only daughters of noble families. The accidental fire destroyed the monastery in 1508 and only abbey church built in 1404-1406 survived. The rebuilt monastery was looted again in 1525 during Peasants War.
Shortly after 1600 the last woman left the monastery. Today a foundation takes care of the preservation of the remarkable ruin.
Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.