The three castles formed the center of power of the Barons of Grünenberg in the Oberaargau region during the High Middle Ages.

Between the 12th and 15th centuries, Grünenberg Castle was a cultural and political center for the nobility that ruled over much of the Oberaargau region.

[1] After the war, the lands and castles were returned to the Grünenbergs after they entered into a treaty with Bern.

[1] In 1452 the last male Grünenberg heir, Wilhelm, died and in 1480 the family sold Langenstein castle to Bern.

In 1850, the municipal president Jakob Käser began to study the ruins, which he documented in a book, the Käser-Chronik in 1855.

From the parking lot in Melchnau Oberdorf, it takes about 10 minutes to follow a well marked trail to the ruins.

The southeast wall was protected by two trenches, which were spanned by a bridge at the original castle gate.