Tasmania’s landscape is largely shaped by one rock — dolerite — often called “the rock that made Tasmania.”
It covers over 30,000 km², nearly 40% of the island, and formed around 175 million years ago during the breakup of Gondwana.
As magma cooled slowly underground, it created columnar joints — the vertical rock formations seen across Tasmania today.
In 1804, botanist Robert Brown recorded that these rocks on kunanyi / Mount Wellington could deflect a compass needle, giving rise to what some call the “Compass Killer” effect.
Dolerite is extremely hard and erosion-resistant — which is why Tasmania’s terrain appears steep, rugged, and sharply defined.
Early settlers even called it “Tasmania’s Curse” because it creates thin, nutrient-poor soils, making farming difficult.
📍 Major Dolerite Locations You Can Visit
• Cape Pillar (Tasman Peninsula)
Sea cliffs rising around 300 metres — taller than the Eiffel Tower’s viewing deck height — among the tallest in the Southern Hemisphere.
• Cape Hauy (Totem Pole & Candlestick)
Thin vertical dolerite sea stacks — some of the most challenging rock climbs in Australia.
• Cape Raoul
Layered “organ pipe” formations that look like a natural stone fortress rising from the ocean.
• kunanyi / Mount Wellington (Hobart)
Home to the Organ Pipes — massive dolerite columns directly overlooking the city.
• Cradle Mountain
Jagged peaks formed entirely from dolerite, giving the mountain its distinct serrated shape.
• Ben Lomond
A high alpine plateau with steep dolerite cliffs — also one of Tasmania’s main snow regions.
• Cataract Gorge (Launceston)
Features large dolerite boulders lining the river, often called the “Guardians of the Gorge.”
• Devil’s Gullet (Central Plateau)
A lookout over a 220-metre vertical drop carved into dolerite rock.
• Overland Track / Mt Ossa region
Multi-day trek surrounded by dolerite-capped mountains, including Tasmania’s highest peak.
Dolerite isn’t just rock — it’s the reason Tasmania looks the way it does.
From cliffs and coastlines… to mountains and valleys — it defines the island.
Would you visit these places in real life?