Udbina Fortress (Gradina)

The ruins of Udbina's medieval fortress, known locally as Gradina, stand on the northern edge of the hill on which the present town is built. From this rocky height the Krbava field divides into two arms, one running east towards Visuć and Kozja Draga and the other south towards Kurjak and Komić, which made the spot a natural lookout over the whole plain.

The oldest known mention of Udbina is a Glagolitic note from 1364 on the back of a Latin charter for the Pauline monastery, written in a tower at Udbina. That tower probably belonged to the Kurjaković family, the counts of Krbava, who held the district from the late 13th century. Radiocarbon dating of burnt wooden beams found during excavation places the start of the stone fortress between the end of the 14th century and the first third of the 15th. In the 15th century, as Ottoman raids grew closer, a fortified settlement took shape with a round central tower on the highest point, an inner wall around the palas and an outer ring of walls protecting the lower town on the east and south sides.

The Battle of Krbava Field in 1493 was fought on the plain below. The Ottomans took Udbina in 1527, repaired the fortress using stone from the ruined Krbava cathedral, and made the town the centre of their new province in Lika and Krbava. Habsburg and Croatian forces recaptured it in 1689 and it passed to the Military Frontier, but after the Peace of Sistova in 1791 moved the border east, the fortress lost its purpose. Local people then took its stone for new houses.

Since 2008 the Museum of Lika in Gospić has run systematic excavations, with ten seasons of digging and six of conservation by 2018. The work uncovered the interior of two irregular round towers. The later tower has walls about 2.4 metres thick and an inner diameter of around 7 metres, with the entrance on the first floor facing north. Finds include pottery, iron and glass objects and stone cannonballs, and below the medieval layers lies a Late Bronze Age Iapodian hillfort.

The ruins sit directly above the Church of Croatian Martyrs, and the stations of a Way of the Cross climb the terraces between them. The site appeals to anyone interested in the Krbava story or simply in a wide view over the plain.