The now dilapidated Mellnau Castle is currently only accessible to a limited extent, but it is still worth a visit. The first written mention of the imposing castle dates back to 1263, where it was referred to as "Elenhouch". It may have been built by Siegfried III. commissioned by Eppstein, the Archbishop of Mainz. He may have built it around 1248 as a replacement for the destroyed Hollende Castle. The 19 meter high keep, which can still be admired today, was completed in 1331 and is therefore almost seven hundred years old.
Mellnau Castle can be seen from far away. If you walk along the "Cuckoo Trail" you can enjoy the view from different sides. From the castle itself you have a wonderful view in all directions.