Erfenstein Castle is a medieval spur castle in the German state of Rhineland-Palatinate. It lies within the Palatine Forest above the Elmstein Valley at 265 m above sea level (NN) in the vicinity of the hamlet of Erfenstein in the municipality of Esthal. Together with nearby Spangenberg Castle, it is linked to the legend of the Leather Bridge.

Spangenberg Castle is the partially rebuilt ruin of a rock castle in the German state of Rhineland-Palatinate. It lies in the Palatine Forest above the Elmstein valley near the village of Erfenstein, but is actually on the forest estates belong to the town of Neustadt an der Weinstraße, or more precisely, the village of Lachen-Speyerdorf. Together with the neighbouring castle of Erfenstein, it is linked to the legend of the Leather Bridge.