Dubovac Castle is the oldest Karlovac monument, not just because of its ample history, but also because of the pioneer decision to preserve it in the name of collective memory. Namely, since 1896, it has already been in the possession of the municipality and open to the public. Its reconstruction from 1952 to 1961 was managed by Greta Jurišić on behalf of the Croatian Conservation Institute. As its owner, the Karlovac City Museum managed Dubovac from 1965 to 2007, and is currently using the defense tower with a belvedere, which was also the venue of the exhibition titled “Around the Rivers of Kupa and Korana”, by authors Lazo Čučković and Željko Kovačić.
Dubovac was named after the once existing oak (dub) forest that surrounded it, and the name was subsequently transferred to a contemporary city neighborhood on the outskirts of Karlovac. Just as they used to say in the 16th century, “Karlovac under Dubovac”, because Dubovac was older and better known, so to this day the castle on the hill above the Kupa River is the most prominent landmark of the cultural and historical landscape of Karlovac, with a view of it opening up from the highway.
The most important template for its 20th century reconstruction was an image by military engineer Krey from 1777, documenting a building of a castle type, constructed mostly in roughly dressed stone, of irregular rectangular ground-plan, fortified by corner towers. The rectangular defense tower stands approximately two floors above three round, two-floor towers, between which are wings with defense, storage and residential rooms. The year 1511 can be considered to be the milestone in construction history, because that was when the then owner, Bernardin Frankopan, mentioned in one of his letters that Dubovac had turned from a mostly wooden, into a stone edifice.
Archeological research has also been conducted since 1997, and has revealed abundant prehistoric and ancient layers of the previous settlement, especially significant in the late Bronze and early Iron Age. In the Middle Ages, Dubovac developed as a settlement with a fort on the edge of Podunavlje (part of the Danube river basin), a mere 100 kilometers from the Croatian Littoral, at the cross-section of river and road routes, and in an area of dense fortified locations. It was first mentioned in 1339, when it got its first parish priest. Frequently written in Glagolitic script, the testimonies of trade and crafts, legal and school life circumstances of Dubovac burghers-freemen, were most numerous in the several decades preceding the ill-fated Good Friday of 1578, when the Osmanlis devastated its city to the ground. The very next year, refugees found shelter in the newly established and quickly built Karlovac, and only the castle remained which, together with the Dubovac estate, was in those years bought from Juraj Zrinski by the War Council that controlled the Croatian military border. Although not large in area, the Dubovac estate was important economically as a regional market town. Its owners were, among others, important noble families, (S)Zudar (1387-1426), Frankopan (1442-1550) and Zrinski (1550-1578), and then the command of the Karlovac Army (1678-1810).