The Taehwagang River cuts across the heart of Ulsan and flows into Ulsan Bay, which is connected to the East Sea. The river basin, which stretches 36 kilometers from east to west and 28 kilometers from north to south, is mostly comprised of mountainous terrain, but there is fertile land on both sides of the river and at the southern end of the river. The river is presently an important source of drinking water for the citizens of Ulsan.

The field around the midpoint of Taehwagang River was left abandoned for a long time before it was founded as Taehwagang National Garden, preserving nature while providing a resting spot to the citizens of Ulsan. The garden is over twice the size of Yeouido Park in Seoul, and consists of natural water and a lush bamboo forest, known as Simnidae Forest, along with canola and forage barley fields. Simnidae Forest was once in danger of demolition as part of the government's flood control plans but remains preserved thanks to community efforts. Preservation efforts led to turning the area into Taehwagang National Garden of today, which took place from 2004 to 2010.