The island is about 395 kilometers long from north to south, with a maximum width of 144 kilometers from east to west. The coastline around the island is about 1,139 kilometers long, including the Penghu Islands, with a total length of about 1,520 kilometers and an area of about 35,915 square kilometers. It is surrounded by the sea, and the overall shape of the island is like a long sweet potato.
The island is surrounded by the sea, which breeds various coastal landforms. The northern coast is mostly headland and rocky coast, the western coast is mostly sandy beaches, sand dunes, lagoons and muddy beaches, the southern bandao is a coral reef coast, and the eastern coast is a fault coast with steep slopes and many cliffs. Rivers and streams are short and fast, including riverbeds with exposed rocks, riverbeds paved with flat sand, straight-flow or meandering rivers, and even rushing back to the bay, waterfalls, potholes and strange rocks, all over the upper reaches of various streams.
Most of the mountains are NNE-NNW. The main mountain ranges are the central mountain range running through the north and south, the Yushan Mountain and Alishan Mountain on the west, the snowy mountain range in the north and the coastal mountain range close to the east coast. These mountains are collectively called mountains. The highest peak is the main peak of Yushan Mountain, with an altitude of 3,952 meters, which is not only the first peak. During the Japanese occupation, it was also the highest peak in Japan, so it was named &”;New Mountain&”;. The island is also the fourth highest island in the world. Hilly areas are mostly in the north and near the mountains, which account for about two-thirds of the total area of the island.
Although the plains and basins are small and scattered, they are densely populated areas. The main basins are Taipei Basin in the north, Taichung Basin and Puli Basin in the middle, and Taiyuan Basin in the east [17]. Jianan Plain, located in the south, is the largest plain. Others include Changhua Plain in the middle, Pingtung Plain in the south, Lanyang Plain in the northeast and east rift valley in the east. The terrain is as flat as a plain, but the platforms with higher terrain are Linkou Platform, Taoyuan Platform, Dadu Platform and Bagua Platform.