Nuandong Valley (literally, Warm Winter Valley) is located in Dongshikeng, Nuannuan District, southeast of Keelung City. There are river swiftly running across, trees towering around, and peculiar cliff landscapes, making the valley an ideal summer resort. Huoshaoliao, upstream, is the place with the highest rainfall in Taiwan. The forest in the valley is complete, with scaly tree-fern the major species. The air is clean and the river is clear, so it is suitable for family visits. It is also an ideal place for watching butterflies, especially the three-spot grass yellow butterfly.
The trails alongside the riverbanks are 2 itineraries. One runs along the cliff, allowing visitors to appreciate the splendid hanging cliff over the river valley. Another spreads next to the valley and connects with the red-brick trail, near a drawing bridge where visitors can see the refreshing and delicate landscapes, which accompanied by the murmuring stream allow one to forget all the troubles in the real world.