Budňanská skála, Geological formation near Karlštejn, Czech Republic

Budňanská skála is a rock exposure on the southern slopes of Javorka featuring layered formations of limestone and shale. The visible stone walls show how ancient seas deposited sediment over time.

This site was recognized in 1972 at an international geological congress as a reference location for the boundary between Silurian and Devonian periods. This designation made it an official comparison point for rock layers studied elsewhere.

Joachim Barrande searched this site for type material in the 19th century, and it is known for finds of the large crinoid cups of the genus Scyphocrinites. The upper part of the exposure holds a Quaternary profile used for Pleistocene stratigraphy.

The formation is accessible from the road between Karlštejn and Srbsko and can be easily viewed from the roadside. Visitors should collect only samples that have already fallen naturally along the road.

The rock layers contain fossilized remains of sea lilies from the genus Scyphocrinites as well as cephalopods and bivalves. These fossils come from an era when this region was covered by shallow ancient seas.