Una Mamea Park Arboretum

Una Mamea Park Arboretum is a small protected natural site in Donji Lapac, in the Lika region of Croatia, close to the border with Bosnia and Herzegovina. It is set in the upper part of the valley of the Una River, one of the most beautiful rivers in the western Balkans, and it is concerned with the landscape, plants and water that make the river distinctive.

The Una is a river of travertine. Where clean, mineral-rich water flows over limestone, it deposits calcium carbonate on moss and plants, and over thousands of years these deposits build natural dams, terraces and curtains of rock known locally as buk. The result is a chain of waterfalls and pools in which the water often takes on a clear green or turquoise colour. The effect is similar to that in Plitvice Lakes, though on a much smaller scale and with far fewer visitors. Near Donji Lapac the river is still young, close to its source, and the landscape is quiet, with wooded slopes, meadows and the sound of running water.

An arboretum is a collection of trees and shrubs displayed and labelled for study and enjoyment. In a protected area like this one, the idea is to present the natural flora of the region and to teach visitors about the relationship between plants, water and rock. A walk along the trails gives views of the river, the travertine barriers and the small cascades, and explains something of the geological and ecological importance of the headwaters. The site is also used for education and research, and it forms part of the effort to protect the natural and cultural heritage of this corner of Lika.

Across the border, the river flows into Una National Park in Bosnia and Herzegovina, where it reaches its most celebrated waterfall, Štrbački buk, a broad cascade that is among the finest sights on the river. Visitors who are interested in the Una often combine the Croatian headwaters with a trip across the border, and the two sides form one continuous landscape. Donji Lapac itself is a small town in a sparsely populated region, and services are limited, so it is wise to bring food and water.

Most visits last one or two hours, and the trails are easy to walk in good shoes. The site can be seen at any time of day, though the light is best in the morning or late afternoon, and spring, when the water is high, is especially beautiful. It suits nature lovers, photographers and anyone interested in rivers and geology.