Posázavské bučiny, Special area of conservation in Prague-East and Benešov Districts, Czech Republic

Posázavské bučiny is a 21.13-hectare nature reserve on the left bank of the Sázava River, opposite the Budín settlement and near Sedliště. It protects beech and scree forests on steep slopes, and includes two railway tunnels (Samopšecký and Ledečský II) and the Bílý kámen site with a 456-metre summit.

The reserve was established on 15 December 2017, covering 21.13 hectares on the left bank of the Sázava opposite the Budín settlement. Its slopes were settled from the Neolithic, and limestone mined there was worked into bracelets and ornaments. From 1032 the nearby Sázavský klášter monastery administered the land, and the Posázavská stezka trade path crossed it in the Middle Ages. Quarrying at Bílý kámen ended in the 1950s.

The reserve lies on the left bank of the Sázava opposite the Budín settlement, and the Čerčany–Světlá nad Sázavou railway runs along its river edge, passing through the Samopše and Ledeč II tunnels. The name refers to the beech woods of the lower Sázava valley. Limestone was mined here from prehistory until the 1950s.

Multiple marked hiking trails traverse the protected area, allowing visitors to explore the forests on established paths. Informational signs along the routes help explain the natural environment as you walk through.

Two railway tunnels, the Samopšecký and Ledečský II, lie inside the reserve's boundary along the Čerčany–Světlá nad Sázavou line on the left bank of the Sázava. The line is seen as a possible route for invasive plants to enter the forest.