Fortica Fortress (Croatian: Tvrđava Fortica) is a ruined early modern fortified structure in the town of Otočac, Lika-Senj County, Croatia. Built on the top of a flat hill at the northern end of the town, it overlooks a large part of Otočac and Gacka River valley. Once a military-defensive stronghold on the line of defense against Ottoman Turks, it turned later slowly, by the end of the Ottoman wars during the 19th century, being uncared-for, into a ruin. Recently, the fortress has been partially restored.