The Devil's Rocks (Čertovy skály)
On the northwestern slope of Háj Hill (Hainberg), between Aš and Podhradí, lies one of the most remarkable geological sites in Western Bohemia – the Devil's Rocks (Čertovy skály). At first glance, they look like a romantic group of rock towers and frost cliffs in the middle of a forest. In reality, they represent an extremely valuable geological site that allows us to literally look back into the ancient history of the Earth's crust. The Devil's Rocks are part of the Egeria National Geopark. Since 2026, they have also been listed in the database of significant geological localities of the Czech Republic, which is managed by the Czech Geological Survey.
A Landscape Millions of Years in the Making
The entire massif of Háj Hill is made of old metamorphic rocks – mica schists and quartzitic mica schists. These rocks were formed by the transformation of original marine sediments during the Variscan orogeny in the Paleozoic era. Today, they form the northern flank of the Fichtelgebirge-Erzgebirge anticlinorium within the Saxothuringian zone.The rock is exceptionally diverse. In the mica schists, you can see glittering flakes of muscovite and biotit, and in some places, small garnet grains or lenses of secretion quartz. The varying resistance of individual layers to weathering created a dramatic landscape of rock towers, fissures, overhangs, and frost cliffs.Traces of ancient tectonic processes – folding, deformation, and fissure systems – are also very clearly visible here. Some almost vertical fissures running northwest-southeast are open and partly filled with iron hydroxides, which give the rocks their rusty shades.A Unique Rock WindowAn exceptionally rare geomorphological feature – the so-called rock window – attracts the most attention from both experts and visitors. This natural opening was created by long-term selective mechanical weathering of the mica schists, mainly by the action of frost over the last hundreds of thousands to millions of years.Such phenomena are extremely rare in the nature around Aš. The rock window can be described without exaggeration as the "family silver" of the Aš region – a unique natural formation that helps create the genius loci of Háj Hill and its surroundings. The site is a textbook example of Quaternary frost weathering processes and represents an important place for the study of geomorphology, structural geology, and metamorphic processes.
Fragile Beauty Needs ProtectionThe Devil's Rocks are recommended for protection as a significant geological locality. The reasons include not only instructive examples of folding and tectonic processes, but also the unique geomorphological structures formed by the selective weathering of mica schists.The biggest problem today is the damage to the rock window caused by the movement of visitors and climbers. Although part of the via ferrata route has been modified, the sensitive surface is still being trampled and worn away. Such impacts can lead to irreversible damage or even the destruction of the entire structure.Visitors should therefore walk through the site with maximum caution and avoid direct contact with the rock window.
Geologists Zdeněk Nepustil (left) and Petr Rojík at the Devil's Rocks (Čertovy skály)
The protection of this unique natural heritage is important not only for geologists and researchers, but also for future generations of visitors to the Aš region.The Devil's Rocks Via FerrataThe site also includes a popular secured climbing route, a via ferrata. It leads through the rock complex between Podhradí and Háj Hill at an altitude of 666 meters. The rock group is located about 2.5 kilometers from the main parking lot of the Háj sports complex along a marked tourist path.The path is also used by cyclists on the purple Faust trail. The via ferrata can also be reached from the Podhradí bus stop, which is approximately 1.5 kilometers away.The via ferrata offers mild to moderately difficult climbing. The route leads in a spiral traverse to the top of the highest rock and, after a bridge crossing, continues to the neighboring rock tower. The difficulty of individual sections ranges from A and B to more challenging vertical parts of grade C. The total length of the secured sections is approximately 80 meters. The Háj sports complex currently offers rental services for ferrata sets and bicycles, and further development of ferrata routes in this area is planned for the future.Basic Information
The Devil's Rocks represent a place where a dramatic landscape, geological history, and modern outdoor activities meet in one of the most interesting spots of the Aš region. You only need to slow down, look under your feet, and look around you – and the rocks will begin to tell a story that is hundreds of millions of years old.
Using the text by Petr Rojík and Zdeněk Nepustil.
Photo author: Zdeněk Nepustil.
Photo 1-3:Podhradí – The Devil's Rocks (Čertovy skály) near Aš