Karlické údolí, Nature reserve in Mořinka, Czech Republic.

Karlické údolí is a nature reserve of 214.1 hectares in the Český kras protected landscape area, the third largest protected area there. A meandering stream, the Karlický potok, divides slopes cut into the Karlštejn plateau; most of the ground is deciduous forest, with rock outcrops on the upper left bank and small islands of dry steppe grassland. The ruins of Karlík Castle stand within the reserve.

Karlické údolí is a nature reserve with registration number 548, administered by the Agency for Nature Conservation and Landscape Protection of the Czech Republic through the Český kras Protected Landscape Area administration. The protected features are the typical forest, plant and animal communities of the Karlštejn Highlands. The ruins of Karlík Castle, now a cultural monument, also lie within the reserve.

The valley's name comes from the hamlet of Karlík, whose castle ruin stands within the reserve and is listed as a cultural monument. The ruin is the only built heritage here; the surrounding slopes are valued for their preserved broadleaf woods and rock steppe.

The reserve is accessible through yellow-marked hiking trails connecting Karlík to Vonoklasy, suitable for different fitness levels. The best time to visit is spring through autumn when paths are dry and forests are in full leaf.

The valley shelters a remarkable variety of mollusk species living in limestone crevices and damp areas that visitors rarely notice. These invertebrates play an important ecological role despite being easy to overlook during a walk through the reserve.