Unška Collapse Doline

10 April 2021 Aerial photographyCavesPanoramas

Unška Collapse Doline is a collapse feature up to 125 metres deep, formed when the roof of a large underground chamber of the River Rak caved in.

On its eastern side, behind sheer walls, underground military bunkers built between the two world wars extend below ground. There were reportedly 15 kilometres of tunnels, but they were later sealed with concrete and flooded, leaving about 1.5 kilometres open to visitors.

Top-down aerial view of Unška koliševka, a pale circular collapse enclosed by dense green forest and winding tracks.

A person descends old stone steps into a narrow, shadowed tunnel at Unška koliševka.

A long narrow concrete passage inside the Unška military tunnels leads towards tiny figures and distant lights.

A visitor looks across the deep, densely forested Unška koliševka from a rocky viewpoint.

A small bat sleeps upside down from a pale wall inside the dark tunnels of Unška koliševka.

Tiny caver hangs on a rope against the immense pale limestone wall of Unška Koliševka above the wooded chasm.

Sunlit white limestone cliffs form the steep rim of Unška koliševka above a shadowed, wooded floor.