Krušnica Spring

Vrelo Krušnice is one of the most beautiful karst springs in northwestern Bosnia and Herzegovina, just five kilometers from Bosanska Krupa, in a wooded and almost untouched valley. The water emerges from a deep spring pit whose bottom cave divers had still not reached in 2008—they descended to 112 meters through underwater galleries of enormous size. The water temperature is a steady 9.6°C, and the high oxygen content places Krušnica in a Class I watercourse and makes it a suitable habitat for salmonids.

The river flows from the spring toward the town, where it joins the Una. The wider Una–Krušnica area was proposed in 2014 for inclusion in the Natura 2000 ecological network, and the karst underground has recorded the olm and bats. Since 1965, the spring has been protected as a natural monument and today it is a favorite destination for riverside walks, nature watching, and ecotourism.