玉山國家公園
Taiwan Provincial Highway No. 21 is a Provincial Highway in Taiwan that begins Tianleng (天冷), Dongshi District, Taichung City, at the intersection with Provincial Highway No. 8 (Central Cross-Island Highway), and ends at Tataka(塔塔加), where it is connected with Provincial Highway No. 18 (New Central-Crossing Highway) in Yushan National Park. It is the primary highway to the Sun Moon Lake, a popular tourist destination. The total length is 145 km.