Taiwan occupies an island in the western Pacific Ocean, approximately 160 kilometers off the southeastern coast of mainland China across the Taiwan Strait. The main island extends 394 kilometers from north to south and reaches a maximum width of 144 kilometers from east to west. Taiwan Island comprises 35,808 square kilometers, making it slightly larger than Belgium. The territory includes several outlying island groups: the Penghu Islands (Pescadores) sit 50 kilometers off the western coast in the Taiwan Strait, while Kinmen and the Matsu Islands lie near the mainland coast of Fujian Province. Green Island (Ludao) and Orchid Island (Lanyu) rise from the Pacific 33 and 65 kilometers respectively off the southeastern coast. The total land area of all Taiwanese territories measures 36,197 square kilometers.
The Tropic of Cancer crosses Taiwan at 23.5 degrees north latitude, bisecting the island through Chiayi County and Hualien County. This line places approximately two-thirds of Taiwan in the subtropical zone and one-third in the tropical zone. The positioning creates distinct climatic variations between northern and southern regions that affect temperature ranges, precipitation patterns, and agricultural seasons throughout the year.
The Central Mountain Range forms the dominant geological feature of Taiwan, running 330 kilometers along a north-northeast to south-southwest axis through the eastern two-thirds of the island. This range contains over 260 peaks exceeding 3,000 meters in elevation. Yushan (Jade Mountain) reaches 3,952 meters, making it the highest point in Taiwan and the fourth highest peak on any island globally. The summit rises in Yushan National Park on the borders of Nantou, Chiayi, and Kaohsiung counties. Snow Mountain (Xueshan) attains 3,886 meters in Shei-Pa National Park, forming the second highest peak. These mountains create a dramatic topographic asymmetry: the western slopes descend gradually across foothills to broad coastal plains, while the eastern slopes plunge steeply to the Pacific Ocean within 20 to 30 kilometers of the ridgeline.
The western lowlands contain three major plains that hold most of Taiwan's population and agricultural production. The Chianan Plain extends across southwestern Taiwan from Changhua County through Chiayi, Tainan, and into Kaohsiung, covering approximately 4,500 square kilometers. The Taichung Basin occupies central western Taiwan around Taichung city, measuring roughly 400 square kilometers. The Taipei Basin sits in northern Taiwan, encompassing Taipei and portions of New Taipei City across 243 square kilometers at elevations between 5 and 20 meters above sea level. These western plains experience annual flooding during typhoon season, historically making rice cultivation the dominant agricultural practice.
The East Rift Valley separates the Central Mountain Range from the Coastal Mountain Range in eastern Taiwan. This valley extends 180 kilometers from Hualien County through Taitung County, varying in width from 6 to 10 kilometers. The valley floor sits between 50 and 300 meters elevation, creating a distinct agricultural zone between two mountain systems. The Coastal Mountain Range rises along the Pacific shore, reaching maximum elevations near 1,600 meters but generally remaining below 1,000 meters. This range resulted from the collision of the Luzon Volcanic Arc with the Asian continental shelf, making it geologically younger than the Central Mountain Range.
Taiwan sits at the junction of the Eurasian Plate and the Philippine Sea Plate. The Philippine Sea Plate subducts beneath the Eurasian Plate along the Ryukyu Trench to the northeast and collides with it directly in eastern Taiwan, generating the uplift that built the island's mountain ranges. This tectonic activity produces measurable uplift rates of 5 to 7 millimeters per year in the Central Mountain Range. The collision zone generates frequent seismic activity—Taiwan experiences approximately 2,000 earthquakes annually that register on seismographs, though most measure below magnitude 4.0. The 1999 Chi-Chi earthquake measured magnitude 7.3 with an epicenter near Nantou County, resulting in 2,415 deaths and demonstrating the ongoing seismic hazard across the island.
Active fault lines cross Taiwan in multiple locations. The Chelungpu Fault ruptured during the 1999 Chi-Chi earthquake, creating surface displacement up to 9 meters vertically and 11 meters horizontally along an 85-kilometer trace. The Longitudinal Valley Fault runs through the East Rift Valley for approximately 180 kilometers, marking the boundary between the Central Mountain Range and Coastal Mountain Range. The Taipei area contains the Shanchiao Fault and Chinshan Fault, both capable of generating significant earthquakes beneath the population center. Building codes implemented after 1999 require structures to withstand magnitude 6.0 ground motion, though older construction remains vulnerable.
The northern coastline faces the East China Sea and displays dramatic erosion features. Yehliu Geopark on the northern coast of New Taipei City exhibits distinctive sandstone formations sculpted by salt weathering and wave action, including the prominent "Queen's Head" formation that has eroded to a neck width of 138 centimeters as of 2019 measurements. The Qingshui Cliffs rise along the eastern coast in Hualien County, where marble and schist cliffs ascend nearly vertically from the Pacific Ocean to heights exceeding 800 meters across a 21-kilometer stretch. These cliffs mark where the Central Mountain Range meets the sea, creating one of the world's highest coastal precipices.
The southern tip of Taiwan terminates at the Hengchun Peninsula in Pingtung County, where the town of Kenting sits approximately 22 kilometers north of the southernmost point at Eluanbi. This peninsula experiences tropical climate year-round, with coral reefs developing along the southern and western coasts. The coastline transitions from the mountainous east to coral limestone formations in Kenting National Park, Taiwan's oldest national park established in 1984 across 333 square kilometers. The area contains uplifted coral reef formations reaching 315 meters elevation at Dajianshan, demonstrating tectonic uplift rates of approximately 5 millimeters per year over the past several hundred thousand years.
Taiwan's offshore islands add strategic and ecological dimensions to the territory. The Penghu Islands comprise a volcanic archipelago of 90 islands and islets, of which approximately 20 maintain permanent populations. Magong city on Penghu Island serves as the administrative center. These islands lack permanent streams, receiving all freshwater from rainfall and groundwater extraction. Kinmen sits 10 kilometers from mainland China's Fujian coast, comprising 12 islands totaling 151 square kilometers. The Matsu Islands lie even closer to the mainland at distances between 9 and 190 kilometers from the Fujian coast, totaling 29 square kilometers across 36 islands. Both Kinmen and Matsu remained under martial law until 1992, decades after Taiwan proper lifted martial law in 1987, due to their proximity to mainland China.
Green Island and Orchid Island rise as volcanic formations in the Pacific. Green Island covers 15 square kilometers, reaching a maximum elevation of 281 meters at the Huoshao Mountain peak. The island contains one of only three saltwater hot springs globally at Zhaori Hot Spring, where volcanic-heated water emerges at temperatures between 53 and 93 degrees Celsius directly on the rocky coastline. Orchid Island spans 45 square kilometers with six indigenous Tao villages maintaining populations totaling approximately 4,700 residents. The island reaches 548 meters at its highest point and receives annual rainfall exceeding 3,000 millimeters, supporting tropical vegetation distinct from Taiwan proper.
Taiwan experiences a subtropical climate in the north and tropical climate in the south, with the Tropic of Cancer serving as an approximate boundary. The island receives substantial influence from the East Asian Monsoon system, which delivers distinct wet and dry seasons to different regions at different times. Northern Taiwan including Taipei receives relatively consistent rainfall throughout the year, with a subtle winter maximum from October through March when northeastern monsoon winds bring moisture from the ocean. Taipei averages 2,405 millimeters of annual precipitation spread across approximately 180 days with measurable rainfall. Southern Taiwan including Kaohsiung and Tainan concentrates rainfall into the May through September period, receiving 90 percent of annual precipitation during this wet season while winter months remain notably dry. Kaohsiung averages 1,885 millimeters annually, concentrated between June and August.