Dausenau is a municipality in the district of Rhein-Lahn, in Rhineland-Palatinate, in western Germany.

St. Castor is the patron saint of the local church.

In an 18th-century seal only the picture of Lady Justice was shown, not a shield with the lion.

The south-eastern watchtower in the historic city wall (most parts of which still exist) is being held for the most leaning tower in the world, outdoing the Guinness record holder, the Leaning Tower of Suurhusen, by 0.03 degrees, according to a 2003 measurement.

However, the Book of Records denied entry, stating it was rather a ruin than a tower.