The fourth installment of the Taipei Grand Hike takes you to some beautiful and quiet corners of Yangmingshan National Park, as well as some of the more popular scenic spots in Neihu. The best thing about this portion is that it has an abundance of water, from the natural and charming stream running alongside Shuangxigou Old Trail, to the manmade Sweet Water Lake, and the easily accessible Yuanjue waterfall.