Bitterbachschlucht, Protected gorge in Lauf an der Pegnitz, Germany.

Bitterbachschlucht is a gorge cut by the Bitterbach stream into Burgsandstein, a reddish, coarse-grained sandstone. Its walls are steep and partly undercut, overgrown with mosses and ferns, with deep crevices, holes and small waterfalls. The stream runs along the gorge floor and dries up in dry years such as 2018 and 2019.

During the Ice Age, alternating cold and warm phases caused the Bitterbach to deposit sand in its old bed and flow eastward as a meandering channel. When the climate turned warmer and wetter, the stream could no longer bypass several knolls of reddish, coarse-grained Burgsandstein and cut through them instead. This erosion created the narrow gorge in the hard rock.

Information panels along the stream explain the local ecosystem and erosion processes to visitors. You can observe how water, rock, and forest interact as you walk through the gorge.

Begin your walk from the outdoor pool parking area on Schützenstrasse, following the red and white trail markers. Wear sturdy shoes with good grip since the paths can be slippery from moisture.

The gorge cuts through Burgsandstein, a reddish, coarse-grained sandstone that elsewhere in the area lies mostly more than 10 metres below the surface and is rarely well exposed. The rock cellars beneath Lauf's old town are hewn from this same sandstone.