Take the MRT to Xindian then get the bus up to Wulai it only costs 40TWD less than a quid. The mountain town of Wulai where you can get a hot spring. I liked Wulai most of the town was built on one side of the river thats where all the shops were and the touristy bits, then if you crossed the bridge you can either get the mini railway or walk to the waterfall area. Everywhere advertised the hot spring i never had one but one day ill go back and have one probably in a hotel, i didnt fancy going into somebodys house and in their private bathroom. After walking back from the waterfall area i sampled some wild boar freshly grilled and bought some rice wine.