River Tracing at Sanjhan
The Sanjhan North River (三棧北溪; Sānzhàn Běi Xī) flows through a southern part of Taroko National Park that's disconnected from the main gorge area. Unlike the Liwu River Valley it remains almost entirely undeveloped as a visitor attraction. So to reach the waterfalls and deep, blue-tinted pools of its Golden Canyon, you'll need to be fit, agile and prepared to join a guided canyoning tour. Some Hualien agencies can help, but indigenous villagers are keen that you engage their own guides through the Pratan Visitor Centre in the village of Sanjhan.
Cycling through the Taroko Gorge grows in popularity each year, but be aware that considerable sections of the main route are in tunnels, others can get narrow, and in holiday periods the road can get pretty busy with coaches. The ascent is fairly steady to Tianxiang (elevation 470m) and many riders make it there and back in a day from Xincheng-Taroko station where bikes can be rented. Alternatively Taroko Lodge offers various permutations of a drive-up/cycle-back bike experience.
For something far more challenging, masochistic riders can take Hwy8 all the way to Dayuling (75km) and on via Hwy14 to Hehuanshan crossing the 3275m Wuling Pass, Taiwan's highest section of public road. Rewards, beyond the physical accomplishment, include world-class mountain vistas as your constant companion. At Guanyun (altitude 2374m), around 4km before reaching Dayuling junction, there's a handy hostel.
The park's excellent guide Trails of Taroko Gorge and Su-Hua Areas is available at the National Park Headquarters which also hands out handy bus timetables and trail maps with clear information on length, times, conditions and things to observe along the way. Ask carefully as to which trails are open and closed. To get this information online, and for how to get permits where necessary, consult https://npm.cpami.gov.tw/en/open.aspx