Saulstari Cliff got its name from the nearby Saulstariņi farmstead. Saulstari Cave (also known as Runtiņa River Cave and Forest Brothers Cave) was formed in loose and heterogeneous sandstone. It was excavated and cleaned in 1990. The Upper Devonian sandstone outcrop of the Gauja Formation with the cave is a protected geological natural monument. Devonian sandstone is a millennia old sedimentary rock, strongly rotted, layered, fractured, friable and poorly cemented.
Legends say that the cave was used as a shelter for the Red Partisans in 1944 and the Forest Brothers after World War II, which is why it is also known as the Forest Brothers Cave.
It is forbidden to climb the sandstone outcrop, go inside the cave or make a fire!