Hot Spring Pool activities in Asia
One of the more stylish hotels along the tourist street, Full Moon has mixed and nude segregated pools with nice views over the Tongshi River. Its private rooms feature wooden tubs. The hotel also offers rooms for overnight stays from NT$2700. Go for the lower cheaper rooms as the views are surprisingly better than higher up.
The Royal looks like a community swimming centre, but it's inexpensive and in the perfect location for an after-hike dip if you've been on the Jia Jiu Liao trail. The resort is across the street from where the bus drops you off in Cheng Gong village.