Not far from the attractive mountain town of Tržič lies a hidden valley that once formed the bottom of the ocean floor. Known as the Dovžan Gorge, the area was almost inaccessible for centuries, but today, it is a popular destination for day trippers and a treasure trove for both geologists and paleontologists.

The Dovžan Gorge was created when the Tržiška Bistrica river cut into sedimentary rocks. Many of the rocks date back 300 million years, and for scientists, the entire area is a bit like a time machine.

The valley is extremely rich in fossils. A paleontologist named E. Schellwein discovered dozens of new species in the Dovžan Gorge, some of them not found anywhere else on earth. Locals are especially proud of karavankina schellwieni and sphaeroschwagerina carniolica. In fact, these two fossilized species became so well-known that they were featured on Slovenian postage stamps.

The gorge is also a delight for geologists. Several interesting limestone pyramids can be found throughout the canyon, and ancient coral reefs are exposed in several places. Caves and waterfalls add to the unusual but always exiting topography of the valley.

For years, however, only locals were aware of the Dovžan Gorge. No roads led into the valley, and steep narrow paths served as the only access. But in 1895, a wealthy local industrialist named Julij Born ordered the construction of a tunnel that opened up the valley. Still used today, the tunnel serves as an entrance into a truly fascinating world.

These days, visitors can follow several interpretive trails and experience the majesty of nature in this Alpine valley that once formed the bottom of the sea.