Declared a protected natural site of national importance in order to preserve unique rock formations.
They represent a group of rock formations on the left bank of the Iskar River, above the village of Lyutibrod - four almost parallel vertical rock walls.
They start almost from the river itself, protrude above it by 50-80 m and rise along the slope. Their length varies from 200 to 400 meters, and the thickness from 2.6 to 7 meters.
The first to describe the Ritli was the Hungarian traveler Felix Kanitz in 1873.
In addition to the description, he also left us an engraving of the rocks and ruins along them. Thus, the Ritli became known to the Central European public.
A little later, the Viennese professor Franz Tula made the first more detailed geological description.
The white Aptian limestones were formed 120 million years ago, when the area was the bottom of the sea.
Then the layers rotated vertically and their slow collapse made possible the formation of this extraordinary natural phenomenon.
The rock walls, called “Litri” or “Ritli” (the side covers of a cart) are vertical layers of solid rocks rising above the surrounding slopes.
Their base is at the level of the Iskar River at an altitude of 250m, and up the slope they reach 850m above sea level. Their formation is due to the different erosion resistance of the layers. The strongest are the layers of limestone, sandy limestone or calcareous sandstone, and the most unstable are the marl layers. Thus, as a result of uneven erosion, the stronger sandstones and limestones have been preserved as high, protruding vertical walls, while the more unstable marl and clay layers between them have been carried away by the waters.
