Burg Katz, built by Count Wilhelm II of Katzenelnbogen in the second half of the 14th century, and used a bastion and military base to protect the Rheinfels Castle.
Together, they formed a fortified bulwark across the Rhine, with a barrier for levying the Rhine toll. After the Counts of Katzenelnbogen died out, Castle Katz and
Castle Rheinfels were besieged, demolished, rebuilt and extended several times in a succession of long-lasting disputes on heritage. It was blown up by Napoleon in
1806 and lay in ruins until it was acquired by the local district at the end of the 19th century, and reconstructed as close as possible to the original design.
Since 1989, it has been a privately owned hotel.