Modřany Gully, Protected natural monument in Cholupice, Czech Republic

Modřany Gully is a wooded erosion-cut valley on the right bank of the Vltava in Prague 12, about 9 km south of the Old Town, spanning 124.88 ha between 214 and 300 m elevation. The Libušský potok and Písnický potok run along its floor, and abandoned quarries expose grey-green greywacke, siltstone and clay slate.

In the 16th century the land belonged to the estates of Komořany, Dolní Břežany and Kunratice, then pasture with scattered oaks, alders and willows along the brook. After the Battle of the White Mountain in 1620 it passed from the Sterns of Hirschfeld to Zbraslav Monastery; in 1785 it came under state administration, in 1827 Prince Frederick of Oettingen-Wallerstein bought it, later selling to the knights of Albert. In the 20th century Modřany municipality owned most of it and began afforestation with robinia and black pine.

The name Modřanská rokle comes from the Modřany district, on whose land the lower, western stretch of the valley lies. A marked nature trail runs the length of the gully, and yellow markings lead from Cholupický vrh to the retention reservoir in the upper part. The valley also holds small playgrounds and, in its western section, a football and basketball court.

A nature trail runs through the gully from west to east; yellow markers lead from Cholupický vrh to the retention reservoir in the upper part. An asphalt path along the brook is a signposted cycle route crossing the whole monument. Small playgrounds and a football and basketball court lie in the western section.

The gully follows the Závist thrust fault, where Proterozoic Štěchov Group rock was pushed over Ordovician Letná strata during the Variscan orogeny; the fault runs roughly through the middle of the valley. In the quarry east of the retention reservoir, grey-green greywacke, siltstone and clay slate are exposed, and about 100 m further west, fissures in the Štěchov greywacke are filled with quartz and rust-coloured limonite residues.