New South Wales, a southeastern state of Australia. The name New South Wales was given to the eastern part of Australia by the British explorer James Cook in 1770, and for 55 years about half of the continent—east of the 135th meridian—was known by that name. Successive proclamations of separate colonies before Australian federation in 1901, and of the Australian Capital Territory in 1911, reduced New South Wales to 309,500 square miles (801,600 sq km), or just over 10% of the national area.

New South Wales is readily divided into four distinct physiographic zones, each extending from north to south. The Coastal Lowlands consists of a succession of short river valleys with small alluvial plains, fronted by a varied shoreline of headlands, surfing beaches, sand ridges, saltwater lagoons, and wetlands. To the west lies a deeply broken band of ridges, spurs, and gorges forming the flank of the Tablelands. This almost unbroken series of plateaus varies in width from 30 to 100 miles. (50–150 km).