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.
Wikipedia https://en.wikipedia.org/wiki/Heidelsburg
Address (Unnamed Road), 67714, Germany
Coordinates 49°16'6.306" N 7°41'33.373" E