Opukový lom u Přední Kopaniny, Natural monument in Přední Kopanina, Czech Republic.

The Opukový lom u Přední Kopaniny is a quarry in a 1.94-hectare natural monument on Prague's northwestern edge, between the D7 highway and K Tuchoměřicům street. Its southeastern wall exposes about twelve metres of Cretaceous beds, including the 80–120 cm layer of golden opuka at the base and the Cenomanian–Turonian boundary.

Quarrying at this site dates back to the 12th century, when workers extracted limestone for the local Rotunda of Saint Mary Magdalene. Later, the stone was also used during major restoration work at Saint Vitus Cathedral.

The site takes its name from the opukovy stone, a yellowish-reddish limestone extracted here that became a well-known building material in the region. Visitors can still see how this stone shaped local architecture and remains valued among sculptors.

The quarry lies on Prague's northwestern edge, between the D7 highway toward Kladno and Slaný and the street K Tuchoměřicům. The main access road from the north, past the quarry manager's buildings, is closed; the quarry wall is reached by a path from the east. Much of the protected area outside the mining space is overgrown.

The quarry contains a distinctive limestone layer roughly 80 to 120 centimeters thick, known locally as golden stone. Sculptors have long valued this rare variety for its unique coloring.