When going from Tainan on the Taiwan Route 20 towards Jiaxian (甲仙), the strip of blue lake that is Nanhua Reservoir (南化水庫) is hard to miss. Besides being a major source of Tainan's water, Nanhua Reservoir is also a leisure area and historical site. Below the dam is the Old Battlefield of Tapani (噍吧哖古戰場), now home to a military history park, eco-park and water park collectively called the Yuanzhilu Leisure Park (源之旅休閒公園). Follow the South 179 City Road along the edge of the reservoir towards the upper end and you will arrive at Guanshan Village (關山里), the most remote and secret village in Tainan. Along the sides of the road you will find many secret places, and when you arrive at Guanshan don't forget to head to the Brown Sugar Farm to see the brown sugar being made by the ancient method. This is a great place for an in-depth tour.