The ruins of several Early Croatian fortresses from the 14th century line the banks of the Krka River: Kamičak, Trošenj, Nečven, Bogočin and Ključica, one of the largest and most significant defensive structures in all of Croatia.
The territory between the Krka and Čikola Rivers, including Promin Mountain, was known as the Promin-Miljevac area in Croatian medieval history. During the Middle Ages, Croatian princes and noblemen erected magnificent fortress-cities here. Today only ruins remain, with the occasional visible tower and wall, which still testify to their former greatness. The fortresses were erected at the edge of the Krka canyon, on both the left and right sides. As well as occasionally serving for defensive purposes, the fortresses also formed the core of individual settlements. The noble Croatian Šubić family built the fortresses Trošenj-grad (Čučevo) and Rogovo on the right bank of the River, while the fortresses on the left bank, Nečven, Bogočin and Kamičak were in the possession of other great Croatian families: Nelipić, Martinušić, Bogetić, Utješinović and Mišljenović. The Nelipić nobles owned what was by far the loveliest of all the fortresses, Ključica, which stood over the Čikola River canyon.
Ključica is the largest and best preserved medieval fortress in Krka National Park.
It was erected by the Croatian noble Nelipić family in the 13th century over the canyon of the Čikola River in order to protect their estate from their rivals, the noble Šubić family. Due to its strategic position, Ključica was often a source of conflict for its masters, the Šibenčani.
In 1546, it was conquered by the Turks who ruled here until 1648 when they were finally forced out. Since then, Ključica has been abandoned and no one ever lived here again.
The ruins of the medieval fortress Kamičak stand between Roški slap and Visovac Lake.
According to preserved historical records from 1345, the Croato-Hungarian King Ludovik confirmed the heritage right of Ivan Nelipić over Kamičak. The later Turkish invasions and their occupation of the entire area meant the loss of the significance of Kamičak, and it was abandoned.
Kamičak is also called Utješinovića Grad by the locals, as the first Croatian Cardinal Juraj Utješinović was born here in 1482. Also born here was Marko Mišljenović, who was appointed Croatian Ban by the Croato-Hungarian King Ladislav in 1506.
The ruins of the medieval fortress Bogočin can be seen on the left bank of the Krka River, on a high rock near the village of Bogatić.
It was likely erected by the Croatian noble Nelipić family, while later it was ruled over by the great Martinušić family. A single, excellently preserved medieval road lead to Bogočin, and the fortress could only be entered via a drawbridge.
In the early 16th century, it was taken over by the Turks and remained in Turkish hands until 1684.
The medieval fortress Nečven was built on the very edge of a cliff on the left bank of the Krka River.
Its original masters were the Nelipić family, owners of the entire Promina-Miljevac region. The estate remained under their ownership until 1421, when it came into the hands of the noble Martinušić family. In the early 16th century, the Turks conquered Nečven and held it until 1688.
The Turks brought their soldier here, and turned it into the seat of the Krka nahija (administrative unit of the Ottoman Empire), and later the sandžakat (district) and kadiluk (judicial centre). After the departure of the Turks, Nečven was torched and half destroyed.
The medieval fortress of Trošenj was raised opposite the fortress of Nečven, on the right bank of the Krka River.
It was once under the possession of the great Croatian Šubić family, who ruled over the entire right bank of the Krka River. It was likely erected to guard and control the strategically important bridge over the River.
The Turkish army took over Trošenj in 1522, where they housed their military units, and built a rounded tower. The invasion of the Venetian army to these regions in 1686 ousted the Turks, and the majority of the fortress was destroyed.