Una

Una National Park was established in 2008 in north-western Bosnia and Herzegovina, next to the Croatian border, and protects some 198 km² along the rivers Una and Unac.

Its value is fluvial. The Una runs over limestone and its water, charged with calcium carbonate, precipitates on contact with mosses and algae, forming travertine barriers over which the river tumbles in stepped waterfalls, an active geological process identical to that of Krka in Croatia or Plitvice. The largest of those formations is Štrbački buk, a fall of some twenty-four metres that is the image of the park, followed by the waterfalls of Martin Brod, where the Unac joins the Una in a succession of drops.

The turquoise colour of the water, the density of the riverine woodland and the presence of rapids have made the Una a destination for rafting and trout fishing. The park also protects beech, fir and black pine woods on the slopes, and is home to otter, brown bear and a varied river and forest birdlife. The valley was a front line during the war of the 1990s, and even today the presence of landmines in some sectors governs access and management.