Prosecké skály

Prosecké skály is a small but remarkably interesting nature reserve on the border of Prague's Prosek and Libeň districts, near the streets Nad Kundratkou and Na Rozhraní. The protected area covers just 1.67 hectares, yet it holds one of the more unusual geological attractions in the Czech capital.

Where do these rocks come from?

Unlike many similarly named sites, Prosecké skály are not a purely natural formation. The visible rock walls are the remains of former quarries carved into Cenomanian sandstone dating back to the Lower Cretaceous period. The exposed rock layers today serve as valuable evidence of how the Bohemian Cretaceous Basin developed across Prague. The lower, lighter sections consist of soft, crumbly white sandstone that was once deposited in a freshwater environment, while the upper layers are coarse-grained, rust-colored sandstones formed under marine conditions. This clear contrast in color and texture draws not only casual visitors but also geologists and earth-science students.

What lies beneath the surface?

One of the reserve's most fascinating features is its extensive system of underground passages, created by historical sand mining. Although sometimes mistakenly described as natural caves, these are in fact artificial mining tunnels. Today, roughly 500 meters of the underground network are accessible, but historians and speleologists estimate that the full extent of the passages may once have reached 5 to 7 kilometers. These abandoned tunnels now serve an important ecological role — several endangered bat species have made them their home, adding further natural value to the site.

Protection and history

Prosecké skály was designated a protected nature reserve on June 29, 1968. The goal was to preserve both the unique geological exposures and the underground ecosystem that shelters protected wildlife. Despite its modest size, the area remains a meaningful part of Prague's network of protected natural sites.

What can you see on site?

The main draw for visitors is the stone observation platform at the top of the rocks. Opened in spring 2016, it is reached via a steel grated walkway suspended above the edge of the former quarry. From the platform, visitors are rewarded with sweeping views over the surrounding neighborhoods, making it a popular spot for a short walk among residents of Prosek and Libeň.

Frequently asked questions

Can you enter the underground passages? The accessible section is about 500 meters long, though visiting the tunnels usually requires an organized tour or occasional open days — access can be limited due to the presence of protected bat colonies.

Are these natural rock formations? Not entirely — the visible rock faces are remnants of former quarrying, although the underlying Cenomanian sandstone itself is a natural Cretaceous-era deposit.

When is the best time to visit? The observation platform is open year-round, but since it's an exposed outdoor spot, warmer months tend to offer the most pleasant conditions for enjoying the panoramic views.

How do you get to the reserve? Prosecké skály sits on the border of Prosek and Libeň, near Nad Kundratkou and Na Rozhraní streets in Prague 9, and is easily reachable by public transport from the city center.