Bunda Cliffs, located on the Great Australian Bight in Southern Australia, is the vast, featureless Nullarbor Plain (is part of the area of the flat, almost treeless, arid or semi-arid country of southern Australia), actually the “world’s largest single piece of limestone”, covering more than an area of 270,000 square kilometers and stretching over 1,000 kilometers from the east to the west.
The area is so flat that the Trans Australian Railway runs across its surface for about 483 kilometers in a fully straight line. However, on the surface of the plain, there are areas of slight depressions where sparse rainfall has slowly dissolved away some of the limestones. There are also places where underground caves or sinkholes have collapsed to form dents on the surface.
But mostly, the plain is horizontally flat and devoid of trees, as its Latin name recommends. The “Nullarbor Plain” ends brusquely at the remarkable “Bunda Cliffs” containing over a 200-kilometer-long precipice curving around the Great Australian Bight. Bunda Cliffs form the southern edge of the Nullarbor Plain which extends far inland.
The white colored base you see near the bottom of the cliff face is Wilson Bluff Limestone. This chalky material was made as part of an ancient seabed when Australia started to separate from Antarctica 65 million years ago. This Wilson Limestone is up to 300 meters thick but only the upper portion is visible in Bunda Cliffs.
Moreover, above the white Wilson Limestone are whitish, grey, or brown layers of limestone or crystalline rock. Few layers incorporate marine fossils as well as worms and molluscs indicating their marine origin. So, other layers are created entirely of marine sediment (foraminifera). The Bunda cliffs are capped by a hardened layer of windblown sand laid down between 1.6 million and 100,000 years ago.
These majestically beautiful cliffs are some 60 to 120 meters high and sheer and can be easily viewed from numerous viewing points along the Eyre Highway east of Eucla and west of Nullarbor roadhouse. However, they are better appreciated from the air. The Eyre Highway, Australia’s main east/west link, follows the line of this remarkable coast less than a kilometer inland.
The highway was named after Edward John Eyre, who along with John Baxter and three aboriginals, set off from Fowlers Bay in 1841 in an attempt to reach Albany in Western Australia across the Nullarbor Plain. Though lack of water and dangerous hardship gave rise to a mutiny and two of the aboriginal boys shot John Baxter and absconded. Eyre and the third Aborigine, Wylie, continued on their journey and completed the crossing in June 1841.
The Eyre Highway was laid precisely a century later in 1941. Therefore, more than a distance of 85 kilometers along the highway, there’re 5 main lookouts on the cliffs with signed, gravel access roads from the highway. The western lookout is the most admired because tourists can walk to pieces of rock jutting out of the cliff that provides a vantage-looking point.
At the eastern end of Bunda Cliffs, there is a lookout at the Head of the Bight where tourists can stay for hours watching Southern Right Whales in the ocean below the cliffs. Whereas on the Southern Right Whales migrate from the sub-Antarctic in the autumn and give birth to calves in inshore water along the southern Australian coast, and then remain in the vicinity for months while the calves put on weight.
Head of the Bight is one of these calving-mating grounds. If you want to see them, then there is a charge but then there is good viewing without environmental damage small price to pay.