Most of the Dobra river is located in the Karlovac County in the Republic of Croatia. Flowing for approximately 65 miles, its basin covers an area of about 350 square miles. The name of the river probably comes from the Celtic word dubrum, meaning water, or deep. The river begins in Gorski Kotar near Skrad and Ravna Gora, where it begins flowing north and then turns east. Flowing southeast into the city of Ogulin, it becomes an underground stream. Finally, the river flows into the Kupa, which is located North of Karlovac.