 The earliest architectural heritage of the region includes ruins of Roman and Byzantine buildings throughout the area and early medieval Croatian burial grounds in the Vinodol area.There are preserved examples of the Romanesque architecture on the island of Krk, in Vinodol, and in the Kastav area—largely churches, monasteries, and fortifications such as Drivenik Castle.Several preserved examples of Gothic churches exist on the mainland, but during the Renaissance, construction largely consisted of fortifications because of the Ottoman conquest of the hinterland of the region.