Burgstall Schlossberg, Archaeological fortification site in Gräfenberg, Germany.

Burgstall Schlossberg is an archaeological site near Gräfenberg with the preserved foundations of a medieval fortified castle. The hilltop location still shows traces of walls and defensive structures that once protected the settlement.

This fortification was built during the medieval period as part of the feudal defense network. The site was abandoned over time and now survives only as earthen remains and buried structures.

The name Heidenstein, still used for the site, is not documented in writing; the castle's own name is unknown. The rock pinnacle left standing in the neck ditch is sometimes called the Opferstein, and the plateau at the tip of the spur now serves as a viewing point.

The burgstall is freely accessible at all times and is used as a viewing point. The ridge is only two metres wide in places, with a vertical rock face dropping about ten metres on the north side, so watch your step. Steps lead down into the unfinished neck ditch; a wooden footbridge crosses the second ditch.

The ground structure reveals the foundations of a medieval castle, providing researchers with data about construction techniques and defensive strategies of the period.