Vrkoč National Nature Monument

The Vrkoč NNM lies in the Ústecký kraj – Ústí nad Labem Region and covers a structurally characteristic rock formation which protrudes from the left-bank slope of the Labe river valley above the Prague to Ústí nad Labem railway line. The monument lies opposite the Střekov Castle on the right bank of the river. The national nature monument was declared in 1966 to protect a dramatic example of columnar jointing of the basalt rock in the shape of an upturned egg. The name “Vrkoč” reflects the colloquial name of the rocks as they look like ladies “tresses” or plaited hair.
 
The main subject of the protection is a preserved seam of olivine basalt with a characteristic fan-like layout of the separated columns, which can best be seen on this elongated formation above the Ústí nad Labem to Prague railway line. The magma which formed the Vrkoč formation penetrated into sandstone strata and gradually solidified under the effects of pressure from several directions. This is how the five or six-sided columns with an average thickness of 20cm and set into their fan-shaped configuration. The side valley of the Podlešínský potok Stream falls steeply into the Labe valley and parallel to the Vrkoč rocks. The lower half of the stream valley is deeply incised into Santonian sandstones, which represent the youngest sedimentary rocks of Cretaceous age in the České středohoří Mountains. A dramatic rock amphitheatre can be found in the upper third of the stream valley and this is built of a capping bed of basaltic vulcanites. A stream flows from above these rocky cliffs, through a narrow gap between the distinctive vertical columns and then over the edge of the rocks to form a 12-metre-high waterfall – the highest in the České středohoří Mountains.
 
The head of the Vrkoč basalt seam was quarried in the mid 19th century in connection with the construction of the railway line. This quarrying helped to uncover the best known example of columnar jointing with a fan-shaped configuration in this country. The cliffs which lie directly beside the railway are 40 metres in height, with a distinct vertical central groove and fan-shaped basalt columns bending away from it to either side.
 
The Vrkoč rock formation is covered with basket of gold (Aurinia saxatilis). In the surroundings we can find typical grove and hygrophyte (damp-loving) plants with many species which are typical for talus and ravine forests.
 
Zoological research has not been carried out here, but the character of the protected area indicates that the monument could play host to a notable invertebrate fauna. An abundant population of fire salamanders (Salamandra salamandra) lives in damp and shaded parts of the monument.
 
The talus and ravine forests with oaks, limes and maples are close to the natural species compositions.
 
The monument lies next to the regional capital Ústí nad Labem and is often visited by the townspeople. Vrkoč also stands above the Labe valley transport corridor (railway, roads, the Labe river). Opportunist trees and shrubs are occasionally removed from the actual rock formation.