Once a large freshwater swamp, the

Once a large freshwater swamp, the habitat of diverse mollusks of about 2 cm in size, Su-san Hoi features a slab formed from a huge number of embedded various types of mollusks which can be dated to approximately 40 million years ago. With changes on the surface of the earth, seawater flooded the freshwater swamp and the limestone elements in the seawater enveloped the submerged mollusks resulting in a homogeneous layer of fossilized mollusk shells forty centimetres thick known as Shelley Limestone. With geographical upheavals, the limestone layer is now distributed in great broken sheets of impressive magnitude on the seashore.