The park stretches for 130 km from Black Point, 35 km east of Augusta, to Long Point 10 km west of Walpole, extending inland for between five and 20 km. It lies 8 km from Northcliffe and 40 km from Pemberton. Qualities of remoteness and pristine natural beauty are features of D’Entrecasteaux National Park (pronounced don-truh-cast-oh, with slight stress on the last syllable). Spectacular coastal cliffs, beaches, mobile sand dunes, vast coastal wildflower heaths and even pockets of karri are all part of the scenery. The park has isolated beach camp sites, wild coastal vistas and excellent fishing. Much of the park is managed for its wilderness values, so few facilities are provided. Major streams and rivers, including the Warren, Donnelly and Shannon, drain through D’Entrecasteaux and empty into its coastal waters. High sand dunes and limestone cliffs on the sea coast give way to coastal heathlands and a series of lakes and swamps further inland. These include Lake Yeagarup and Lake Jasper, which is the largest freshwater lake in the southern half of Western Australia. Vast areas of wetlands behind the coastal dunes are known as The Blackwater. Another outstanding feature is the Yeagarup Dune, an impressive mobile dune 10 kilometres long. The D’Entrecasteaux National Park and its inland neighbour the Shannon National Park surround one of Western Australia’s largest inlets. Broke Inlet is also the only large estuary in the South-West that has not been significantly altered, either by developments along its shores or within its catchment area. Lying at the park’s eastern end, it is a large, shallow estuary, linked to the ocean by a narrow seasonally open channel that passes through high ridges of windblown sand dunes. Sandy beaches along its shores are interspersed with low, rocky headlands of gneiss. The gneissic basement projects above water level in many places to form several small islands. The basalt columns west of Black Point are one of the park’s most stunning landforms. This feature originated from a volcanic lava flow, some 135 million years ago. The formation resulted from the slow cooling of a deep pool of lava, similar to the development of mud cracks. In the process of it cracking and shrinking, columns were formed perpendicular to the surface. The result was a close-packed series of hexagonal columns, now slowly being eroded by the sea.