Tasmania, the largest island of Australia, has a landmass of 68,401 km2 (26,410 sq mi) and is located directly in the pathway of the notorious "Roaring Forties" wind that encircles the globe. To its north, it is separated from mainland Australia by Bass Strait. Tasmania is the only Australian state that is not located on the Australian mainland. About 2,500 kilometres (1,300 nautical miles) south of Tasmania island lies the George V Coast of Antarctica. Depending on which borders of the oceans are used, the island can be said to be either surrounded by the Southern Ocean, or to have the Pacific on its east and the Indian to its west. Still other definitions of the ocean boundaries would have Tasmania with the Great Australian Bight to the west, and the Tasman Sea to the east. The southernmost point on mainland Tasmania is approximately 43°38′37″S 146°49′38″E / 43.64361°S 146.82722°E at South East Cape, and the northernmost point on mainland Tasmania is approximately 40°38′26″S 144°43′33″E / 40.64056°S 144.72583°E in Woolnorth / Temdudheker near Cape Grim / Kennaook. Tasmania lies at similar latitudes to Te Waipounamu / South Island of New Zealand, and parts of Patagonia in South America, and relative to the Northern Hemisphere, it lies at similar latitudes to Hokkaido in Japan, Northeast China (Manchuria), the north Mediterranean in Europe, and the Canada-United States border.
The most mountainous region is the Central Highlands area, which covers most of the central western parts of the state. The Midlands located in the central east, is fairly flat, and is predominantly used for agriculture, although farming activity is scattered throughout the state. Tasmania's tallest mountain is Mount Ossa at 1,617 m (5,305 ft).[1] Much of Tasmania is still densely forested, with the Southwest National Park and neighbouring areas holding some of the last temperate rain forests in the Southern Hemisphere. The Tarkine, containing Savage River National Park located in the island's far north west, is the largest temperate rainforest area in Australia covering about 3,800 square kilometres (1,500 sq mi).[2] With its rugged topography, Tasmania has a great number of rivers. Several of Tasmania's largest rivers have been dammed at some point to provide hydroelectricity. Many rivers begin in the Central Highlands and flow out to the coast. Tasmania's major population centres are mainly situated around estuaries (some of which are named rivers).
Tasmania is in the shape of a downward-facing triangle, likened to a shield, heart, or face. It consists of the main island as well as at least a thousand neighbouring islands within the state's jurisdiction. The largest of these are Flinders Island in the Furneaux Group of Bass Strait, King Island in the west of Bass Strait, Cape Barren Island south of Flinders Island, Bruny Island separated from Tasmania by the D'Entrecasteaux Channel, Macquarie Island 1,500 km from Tasmania, and Maria Island off the east coast. Tasmania features a number of separated and continuous mountain ranges. The majority of the state is defined by a significant dolerite exposure, though the western half of the state is older and more rugged, featuring buttongrass plains, temperate rainforests, and quartzite ranges, notably Federation Peak and Frenchmans Cap. The presence of these mountain ranges is a primary factor in the rain shadow effect, where the western half receives the majority of rainfall, which also influences the types of vegetation that can grow. The Central Highlands feature a large plateau which forms a number of ranges and escarpments on its north side, tapering off along the south, and radiating into the highest mountain ranges in the west. At the north-west of this, another plateau radiates into a system of hills where takayna / Tarkine is located.
The Interim Biogeographic Regionalisation for Australia divides Tasmania into 9 bioregions:[3] Ben Lomond, Furneaux, King, Central Highlands, Northern Midlands, Northern Slopes, Southern Ranges, South East, and West.