National Park "Krka", one of eight Croatian national parks, covering an area of 109 km2 of upper and middle flow of the Krka River, as well as the low flow of Čikola River and its mouth to Krka. This area was declared a National Park in 1985. Krka River flows in a total length of 72.5 km, 50 km of which are under the protection as a unique natural phenomenon, with seven waterfalls and a total altitude drop of 224 m.
The most attractive part of the Krka National Park in Drniš area is Roški slap (Roški Waterfall). The length of its travertine barriers is approximately 650 m, the maximum width of the river flow is 450 m and a total drop of the waterfall is 22.5 m. At the tallest part of the waterfall, 15 meters high, the river dives into Visovac Lake. River canyon is interesting because of its distinctive and rich vegetation. In 1909 the first hydro power plant in Europe was built precisely at Roški Waterfall. Today at Roški Waterfall numerous mills, stamping and rolling mill, which are now ethnographic monuments, have been preserved and restored bearing witness to the economic history and the rural architecture of the region.
Visovac, known as Our Lady’s Island, represents the perfect harmony of nature and human creativity. The small island, on which a Franciscan Monastery of the Mother of Mercy is built, was settled by the Augustinians in the 14th century. Franciscans came to the island in 1445. Later, in 1568 a seminary with a library and archive was founded. Till this day the Monastery still holds a valuable museum collection which contains four incunabula, among which are the Aesop's fables printed in 1487.
From Visovac Lake to Roški Waterfall one can also walk – following the educational trail Stinice – Roški waterfall - Oziđana cave. The route is rich with biological and geological phenomena, and 8 and a half kilometers long. It is interesting to note that in the final part of the promenade there are more than 600 stairs. These stairs, besides being a phenomenal viewpoint, lead to the entrance of the Oziđana cave, which holds evidence of continuity of life in these areas all the way back to Neolithic Age (5000 to 1500 years B.C.). The cave contains interesting exhibits and is fully equipped for visitors. Those who do not wish to hike the entire trail and then climb up the stairs, can access the cave from Miljevci direction, where a parking space is arranged. On the way down, one can also enjoying the fantastic scenery.
Roški Waterfall and Visovac Island can also be visited by car or by excursion boats of NP Krka. Boat ride starts in Skradin and goes up to Skradinski buk, further upstream towards Visovac, Roški Waterfall, and the Monastery of St. Archangel in Kistanje. This Orthodox monastery, first mentioned in written documents in 1402, was built by the Serbian princess Jelena, sister of the Serbian Car Dušan and the wife of the Croatian noble, Duke Mladen III. ŠubiĆ. The Monastery has a large library, full of historical manuscripts and books. A boat ride on Krka is a chance to enjoy the unique natural beauty of the river, the rich flora and fauna, and see numerous monuments and sacral buildings.