The county of Nantou is located in the center of the island of Taiwan and is the only one of all counties not to have a sea coast. The county is largely part of the central mountain chain of Taiwan. Only in the west are the foothills of the flat and hill country of West Taiwan the circle area.
Nantou and Caotun are the two largest cities. To the south of the county lies the Yu Shan, surrounded by a national park, the highest mountain in Taiwan and East Asia with 3,952 m. The central district around the town of Puli is located on the western side of the main ridge of the mountains. There is the Sun-Moon-Lake.