The rock complex of Tustan is composed of eroded remnants of sub-vertically incident sandstone layers of the Yamna formation of the Palaeogene.
They are characterised by the nearly vertical bedding of sedimentary strata with their exotic mattress-like and globe-shaped textures.
The form and character of the rocks depend on weathering conditions and the lithologic composition of sandstone.
During the Mesozoic and the Paleocene Epoch of the Cenozoic, during the time of the then-existing Tethys ocean, thick layers of silt accumulated here.
About 25 million years ago, in the Paleocene Epoch of the Cenozoic, along with the formation of the Carpathian Mountains, sandstones were formed, some of which rose to the surface.
In geology, they are known as Yamna sandstones; the name is derived from the former village of Yanma.
The complex of Urych rocks is made of separate remnants: Kamin (Ukr. “
rock”), Ostryi Kamin (Ukr. “
jagged rock”), Mala Skelia (Ukr. “
small cliff”), Zholob (Ukr. “
ravine”).

In some places, sandstones jut out as great monoliths, in other places, they are chaotically piled boulders.
There are many cracks, recesses, and small caves, including man-made.
The rock complex of Tustan is composed of eroded remnants of sub-vertically incident sandstone layers of the Yamna formation of the Palaeogene. They are characterised by the nearly vertical bedding of sedimentary strata with their exotic mattress-like and globe-shaped textures. The form and character of the rocks depend on weathering conditions and the lithologic composition of sandstone. During the Mesozoic and the Paleocene Epoch of the Cenozoic, during the time of the then-existing Tethys ocean, thick layers of silt accumulated here. About 25 million years ago, in the Paleocene Epoch of the Cenozoic, along with the formation of the Carpathian Mountains, sandstones were formed, some of which rose to the surface. In geology, they are known as Yamna sandstones; the name is derived from the former village of Yanma. The complex of Urych rocks is made of separate remnants: Kamin (Ukr. “rock”), Ostryi Kamin (Ukr. “jagged rock”), Mala Skelia (Ukr. “small cliff”), Zholob (Ukr. “ravine”).
In some places, sandstones jut out as great monoliths, in other places, they are chaotically piled boulders. There are many cracks, recesses, and small caves, including man-made.
Fortress of Tustan