Yuntan Waterfall is a large two tiered waterfall near the possibly permanently closed Alishan Railway near Ruili. Overall there are about 10 waterfalls and a lot of great hiking trails in the area. You can stop at the nearby Yuantan Visitor Center for a good guide map (English).
The hike: The hike is short but it’s also all downhill through a bamboo forest. There is a well built pavilion to rest at or avoid a rain shower near the falls. The trail to the lower falls leaves from the pavilion but was closed when I visited (05/2012).
How to get there: Take the 3 freeway to the Zhuqi Interchange and turn east on highway 166. It will take less than another hour to get to Yuntan Waterfall (1/2 km before Yuantan Ecological Park). Highway 166 is a twisty road that winds up the mountain. It makes for an excellent scenic drive even if you don’t visit the waterfalls.
GPS info: parking N23.53173 E120.65586 – waterfall N2353326 E120.65560
Other info: free – bathrooms – some snacks and drinks, possibly Taiwanese meals