The only exterior visible tower "Katz" illustrates the ongoing conflict between the Counts of Trier and the Counts of Katzenelnbogen, just like its counterpart, the castle "Maus".
The name "Katz" was given to the castle in St. Goarshausen by popular tradition, which actually originated in 1371 as Castle New-Katzenelnbogen. With it, the Counts of Katzenelnbogen aimed to protect their possessions along the Rhine and particularly the customs office in the opposite St. Goar - while consciously establishing a counterweight to the Trier castle "Maus", which threatened their customs operations. Like many Rhine castles, it ultimately could not withstand the French troops, and the castle was destroyed in 1806. It took almost a century before a historicist reconstruction between 1898 and 1899 transformed the ruin into a magnificent residence.

The castle is in private ownership.