Shell Beach (Photo Credit: Brian W. Schaller (Own work) [FAL], via Wikimedia Commons)

Earlier this year, National Geographic released a list of the world’s 21 most beautiful beaches. High among them, especially for sea-shell lovers, is Shell Beach. Located in the Shark Bay World Heritage Area in Western Australia, it is home to a 37-mile (60 km) stretch of white cockle shells.

What makes the beach even more unique is that the billions of shells, which run as much as 32-feet (10-meters) deep in some areas, all come from a single species of mollusk – the Shark Bay cockle (Fragum erugatum). Found only in Western Australia, the marine bivalve mollusk, which measures less than 14 millimeters long, spends its life burrowed into the seafloor between depths of 3.9 feet (1.2 meters) and 21.3 feet (6.5 meters) in many areas of the bay.

Cockle Shells of Shell Beach (Photo Credit: By Lpm43792 (Own work) CC BY-SA 3.0 via Wikimedia Commons

The tiny creatures thrive in the area due to Shell Beach’s location in the horseshoe-shaped Shark Bay’s innermost region which keeps it sheltered from high tides. Additionally, thanks to the low precipitation, the area of the Indian Ocean is also known for high salinity. The excessive salt is not conducive to their predators, which include the starfish and marine catfish, allowing the Shark Bay cockle population to live and breed peacefully.

The combined weight of the prolific shells has compacted the lower layers into a type of sedimentary rock called coquina. Before Shark Bay was proclaimed a World Heritage Site in 1991, the stones were quarried by the locals for use as building materials. While coquina can now only be taken to maintain historic structures, many of the shelly limestone structures can still be seen in the area.

Coquina shell structures (Photo Credit: gdaywa.com)

Though the shells are probably the primary attraction, the beach is also a haven for weak swimmers or young kids, due to the calm, highly saline ocean waters that makes floating a cinch.

Resources: Wikipedia.org, australiacoralcoast.com,perthnow.au, odditycentral.com