Skalka, Natural monument in Smíchov, Czech Republic.

Skalka is a 9.82-hectare natural monument on the slopes of the hill of the same name, on the left bank of the Vltava between Motol and Smíchov, in the Smíchov cadastre of Prague 5. Its core is a quarry in Řevnice quartzite in the western part, where the rock forms ridges called "goat backs"; the ruin of the Skalka homestead also stands on the site.

Quarrying at Skalka dates to the 10th century, when opuka was extracted; in the 19th century the Řevnice quartzite was mined for paving setts until the end of 1913. In 1688 the Italian general Filip Ferdinand de la Crone bought the land, and Praguers corrupted his name to Ladrone, giving the quarry its U Ladronky name. The natural monument was declared on 29 April 1968.

The quarry in the western part is called U Ladronky, after the Italian general Filip Ferdinand de la Crone, who bought the land in 1688; Praguers mangled his name into "Ladrone". The protected area now serves as a city park for residents of the surrounding Motol and Smíchov housing.

The monument lies between Plzeňská street on the south and Pod Kotlářkou street on the west, with family houses bordering it to the north and east. The quarry is in the western part; the terrain rises from 250 to 308 metres. No protective zone was separately declared, so a 50-metre buffer around the boundary applies.

The quarry's name comes from Italian general Filip Ferdinand de la Crone, who bought the land in 1688; Praguers mangled his name into "Ladrone", so the quarry is still called U Ladronky. Geologists long overlooked it in quarry registers, and it appeared under different names: Lom Kotlářka, Lom na Zámečnici, Lom na Ladronce.