This place has an unusual whirlpool feature where the Wushanling Tunnel (烏山嶺隧道) feeds into Wushantou Reservoir (烏山頭水庫).The scenery of Xikou Valley (西口溪) is beautiful and secluded, and it has long held the nickname of “Little Switzerland” (小瑞士).
The whirlpool feature was actually created by the Japanese hydraulic engineer Hatta Yoichi (八田與一). When the Chianan Irrigation System (嘉南大圳) was built during the Japanese Colonial Period, Yoichi was concerned that Wushantou’s water supply was insufficient, so a 4 kilometer water channel was built into the belly of Wushanling to take water from Tsengwen River (曾文溪) at the eastern end to Xikou and into the reservoir. Because the drop in elevation is large, a rapidly swirling hole is created in the water, which became known as the “courtyard whirlpool”. In the future the shaft will be raised by 5 meters, and the whirlpool will be hard to see.