NOTE:
The Tunnel of Nine Turns (Jiuqudong) Trail is closed due to severe damage caused by 403 Earthquake and typhoons in 2024. On April 3, 2024, a magnitude 7.2 earthquake struck Hualien, followed by the impact of Typhoon Kong-rey on October 31, causing severe damage to the park east section of Taroko Gorge including this trail.

The Tunnel of Nine Turns (Jiuqudong) Trail used to be part of the old Central Cross-Island Highway (Provincial Highway 8). In order to relieve the traffic of Central Cross-Island Highway, allow the tourists to enjoy the view of the gorge, and ensure tourists’ safety, Taroko National Park Headquarters devised the plan of vehicle-pedestrian separation. In 1996, Tunnel of Nine Turns (Jiuqudong) Tunnel was open for vehicles, whereas the original section of Central Cross-Island Highway was transformed into a walking path for pedestrians, which allows tourists to enjoy the scenery of Taroko Gorge at ease without the interference of vehicles.

The 1,220m-long Tunnel of Nine Turns (Jiuqudong) Tunnel is the longest tunnel of the Central Cross-Island Highway, while the 700 meters long Tunnel of Nine Turns  (Jiuqudong) Trail is the best part of Taroko Gorge. The trail snuggles against the tall mountain and deep gorge. If you look down, you will see Liwu River gushing swiftly past the mountain walls facing each other so closely. You will be astonished at the craftsmanship of nature that has created these treacherous terrains.

Geology
The mountain walls near the west trailhead have numerous rock crevices extending upwards, which are so-called "faults". The faults resulted from broken and displaced rocks caused by tectonic movement. Because of the drastic orogenic movement, faults are easily seen within Taroko National Park.