The Mauseturm and the ruins of Burg Ehrenfels

Here's some info about the castle:

On the Rhine island at Binger Loch the pretty little Mauseturm strikes our eye. It was probably built in the 13th century as a lookout tower for Ehrenfels Castle, which in spite of its towers and outworks had no view of the Rhine to the north. This is where the tower's name came from since mausen means to be on the lookout, the way a cat is on the lookout for a mouse. Legend, however, has another interpretation: the hardhearted Bishop Hatoo is said to have sought refuge in the tower from a horde of mice; in vain, the mice swam after him and devoured him.

The tower and Ehrenfels castle were partly destroyed by Swedish troops in 1636 and then completely ruined by the French in 1689. The Romanticist on the Throne, King Friedrich Wilhelm of Prussia, had the base of the outwork propped up and repaired and then the tower rebuilt in 1855 in Neo-Gothic style. From then on until 1974 the tower served Rhine navigation purposes as a signal station.

The ruin in the midst of the vineyards above the Mausenturm is what is left of Burg Ehrenfels. The castle along with its subsidiary buildings, used to stretch right down to the Rhine, the final building right next to the river being the customs house.

It was built around 1215 as a customs fortress and passes into the possession of the archbishops of Mainz around 1270. Because of its strategic importance, the archbishops of Mainz around 1270.

Because of its strategic importance, the archbishops had it reinforced many times and used it as a hiding place for Cathedral treasures in times of war.

Ehrenfels has remained a ruin since it was destroyed by the French (1689). With its mighty curtain wall facing the hillside flanked by towers, it is one of the most impressive constructions along the Rhine.

This castle is not open to the public due to danger of collapse.