Birrida Bash - 7104 Birridas, Shark Bay, Western Australia. Limited Edition 10 Birridas were landlocked saline lakes between sand dunes when sea levels were higher than today. A drop in sea level dried the lakes and left the salty hollows we know as birridas today. They range from circular or oval depressions about 100 metres in diameter to elongated depressions several kilometres long. They are among Shark Bay’s visual attractions and ‘superlative natural phenomena’ – reasons for Shark Bay’s World Heritage listing.
