Heidelsburg

The Heidelsburg, also called the Bunenstein, is an old fortification in the western Palatine Forest in the German state of Rhineland-Palatinate that goes back at least to the days of the Roman Empire. Today only the remains of two gates, together with their steps, the castle walls and a cistern have survived.

The castle ruins lie 3 kilometres southeast of Waldfischbach-Burgalben on a rocky ridge of the Drei-Sommer-Berg at a height of 340 metres above sea level above the valley of Schwarzbachtal.

Source: Wikipedia