How the Pinnacles Took Shape
The Pinnacles rise from the shifting sands of Western Australia’s Nambung National Park, but their rock began as countless tiny marine shells. Over time, shell fragments accumulated and became limestone, forming part of the region’s coastal dune system.
Rainwater can dissolve limestone’s calcium carbonate and carry it through sand. As the water moves and evaporates, the mineral can settle again, cementing grains into harder rock. Geologists have proposed that this process helped create the Pinnacles, though their precise formation remains debated.
Sand Reveals the Stone
Wind and water wear away loose sand more readily than solid, cemented limestone. As the surrounding material eroded or shifted, more resistant columns were left standing. Some pinnacles are short and blunt; others rise in narrow points, reflecting differences in the rock and how it has weathered.
That continuing movement is part of the landscape’s character: the yellow sand can bury the bases of the pillars, then expose them again. The result is a field of stone forms that seem architectural, though each is shaped by shell, mineral-rich water, and erosion—not by builders.
