Frankenberg Castle built during the reign of Charlemagne, just because all the legends of the castle is associated with the name of the structure is definitely a great ruler .  Thus, the most famous legend says that at the time of the wedding ceremony with Karl Frastradoy snake appeared among the guests with a small ring in the mouth .  The ring she threw a cup filled with wine, and the cup was at this time in the hands of the emperor, who took an event of good omen, and put a ring on the finger of the spouse .  After that, he began to love his wife like a man possessed .  Even after the death of Frastrady, it was difficult to leave her lifeless body .  He did not agree to bury her, day and night spent inconsolably over her body, but this time his empire fell into decay .  When he finally fell asleep, the court threw the ring in the forest pond, after which the emperor alive again .  But since he always had to go back to the castle in order to find peace there .

After his death, a fairly long period of time, the castle passed to different owners, destroyed, was once even partially flooded. In the period 1941-1945, the castle was located in a special laboratory of Professor Hugo Junkers famous. He is the creator of the German fighter planes.

After a decade and a half after the war, the castle has been completely restored, but occasionally it is closed for repairs to preserve for future generations. In one of the rooms opened a museum that is dedicated to the history of the German town of Aachen. Now the castle is one of the cultural centers where various activities of a public nature.