Croatian center for indigenous karst water fish and crab varieties
- The Gacka River is the third longest subterranean river in the world
- The original stream is 32 m long (today 11 m)
- The most powerful springs: Tonković Vrilo, Klanac and Majerovo Vrilo
- The subterranean area of Gacka is one of the most endangered karst areas in Croatia
- The Gacka field and its surroundings are home to 12 localities which are candidates for NATURA 2000
- The Gacka Springs have been declared as a natural monument and the Gacko and Dabarsko fields as significant landscapes.
The Gacka Valley is a great karst field, surrounded by Velebit in the sea direction and by Kapela in the mainland direction. The water of the Gacka River is exceptionally clean and rich in oxygen, so there are many protected plant species growing in the river.
There old mills “malenice” placed on the Gacka’s springs, some of which were renewed on the traditional style. The residents who lived in the Gacka Valley (gačani) used “plavi” to get around the river, vessels, carved from fir logs. The oldest evidence of human activity in the valley stems from the Mesolithic Age, and this area was of great importance in the later Croatian history, as well. The flora and fauna of the river are both very numerous. The water undergrowth is lush due to the favorable water temperature, beneficial chemical properties, silty bed, from moss and algae to stalk-shaped plants
While visiting the Gacka Valley, you can visit its springs on the Majerovo and Tonković Vrilo, buy freshly milled flour, taste some freshly caught trout, ride a bicycle, take photographs of aquatic birds, go kayaking, ride a Quad, visit the Gacka Museum, and do many other activities.
Within the Visiting Programme to the Croatian center for indigenous karst water fish and crab varieties, there are possibilities of visiting a lookout over the Gacka Valley and taking photographs of it, walking along the educational wooden trail with a bridge over the Pećina spring, and visiting Pećina, the oldest archaeological finding site in the Otočac area.