Caves of the Cape - Leeuwin-Naturaliste NP

The Leeuwin-Naturaliste Ridge is a unique geological feature stretching from Cape Naturaliste to Cape Leeuwin. It is composed mostly of Precambrian hard crystalline rocks (commonly called granite) capped by limestone and occasional sand dunes.

The ancient Precambrian granulite and granitic gneiss can be seen at many headlands along the coast and has been dated at 2,000 million to 650 million years old. Capping these rocks is an extremely young Tamala Limestone, formed during the Pleistocene epoch (over the last 2 million yeears) from fragmented shells, calcareous algae and other material such as silica sand, originally laid down as sand dunes.

This type of limestone is much softer than the older, crystalline limestones more commonly encountered through the rest of the world, making it ideal for the fomation of caves.

Caves are formed as water seeps or flows through it. Many follow path of an underground stream or take on a maze-like form if formed at the water table. The calcium carbonate that is dissolved in the seeping water is redeposited to form a vast array of stalactites, shawls, flowstones and other decorations. The young limestone, being particularly soluble, creates exceptionally well-decorated cave chambers.

It is, of course, vital not to handle the formations, as they are brittle and highly susceptible to damage. Their growth is impeded by the minuscule deposits of skin oils, acids and dirt on our hands. In the past, careless cavers have substantially damaged the caves, leaving rubbish, footprints, eroded areas and broken crystal in their wake. We now know much more about the delicate and irreplaceable nature of caves, and have devised ways to protect them while still allowing access.

Calgardup and Giants caves are not electrically lit. They are self-guided, providing a natural experience of the cave environment. Visitors are equipped with helmets, lamps and information for their very own discovery of of these subterranean wonderlands.

The Department of Environment and Conservation manages two caves in this region, Calgardup Cave and Giants Cave. The Ngilgi Cave is managed by the Cape Naturaliste Tourism Association (opens in a new browser window) and the remaining tourist caves — Mammoth, Lake, Jewel and Moondyne — and the Caveworks Visitor Centre are managed by the Augusta-Margaret River Tourist Association. (Opens in a new browser window.)