The Taehwa River flows into the Bay of Ulsan in the East Sea (Sea of Japan). The river's entire 46-kilometer course lies in the within the metropolitan city of Ulsan. The Taehwa drains an area of nearly 645 km²; much of this lies within Ulsan, but portions of it lie in neighboring cities such as Gyeongju. The river begins in Ulju County, from the mountains Gajisan (가지산, 迦智山:1,240m) and Goheonsan (고헌산, 高獻山:1,033m).