National Park Una is spread through the valley of the upper stream of the river Una as well as through the valley of the river Unac, right tributary of Una, all the way to the river Krka in the west. This area represents a unique natural complex in this part of Europe, very valuable for the conservation of the total landscape and biodiversity.
In terms of cultural and historical area, this area abounds with a rich heritage of archaeological sites and historical monuments, and the special position of the area on the transit line to the sea led it under the influences of many cultures in the past, from where the rich archaeological sites date, remains of medieval fortresses and religious buildings of different faiths and cultures.
The specificity of the river Una is its excessive length of "travertine" flow, with a range of associated phenomena (caves of tufa, travertine islands, barriers and waterfalls), and with extreme forms of pits (Martin Brod, Kulen Vakuf, Klisa, Lohovo) and the cliffs of a canyon-type, upstream and downstream of Martin Brod and downstream of Štrbački buk.
River Unac has a characteristic shape of its karst flow, especially in its lower part, where it sinks and rises more times at the passage through the canyon, and at the end at the Black well, which by its characteristics and beauty belongs to a particular natural phenomenon.
National Park ''Una'' covers the area of 19. 800 ha and is the "youngest" National Park in our country.
