Kobyla, Nature reserve in Koněprusy, Czech Republic.

Kobyla is an 18.5-hectare nature reserve in the Český kras protected landscape area, about 1.5 km southeast of Koněprusy. Its northern part contains the former Na Kobyle limestone quarry, where the Očkovský přesmyk thrust fault is exposed, with artificially cut rock walls and small fen wetlands. The southern part is wooded with oak-hornbeam stands and former pastures now covered by dry grasslands.

Limestone was quarried at the Na Kobyle site and hauled to Beroun for cement production until mining stopped in 1929. In 1967 the quarry area was protected as a chráněný přírodní výtvor called Lom na Kobyle. In 1999 the Český kras landscape-protection administration issued a decree establishing the Kobyla Nature Reserve.

The reserve lies on the geological educational trail Zlatý kůň, and its name comes from the former limestone quarry Na Kobyle. In the 1980s, rock plants such as Saxifraga rosacea and Saxifraga paniculata were introduced onto the quarry walls; some species still grow there and have spread on the southeast side.

Visitors can explore the area using marked pathways and should follow conservation guidelines to help protect the environment. The best time to visit is during warmer months when the diversity of plants and wildlife is most visible.

The former quarry wall exposes the Očkovský přesmyk, a thrust fault where Silurian and Devonian limestones were pushed over younger Lower Devonian Slivenec limestone during the Variscan orogeny. Two caves open in the quarry: Chlupáčova sluj, about 25 m long, with Middle and Upper Palaeolithic stone tools, and Zlomená sluj, about 20 m long, where bones of cave lion, woolly rhinoceros and cave bear were found. Bats hibernate in Zlomená sluj, so it is closed to the public.