The living stromatolites at Hamelin Pool are directly descended from some of the oldest fossils known which date back to about 3.5 billion years ago.  

Hamelin Pool Marine Nature Reserve

Hamelin Pool Marine Nature Reserve is located in the Shark Bay World Heritage Site of Western Australia adjacent to the historic Hamelin Pool Telegraph Station about 30 kilometres (19 mi) west of the Overlander Roadhouse on the North West Coastal Highway. Access is via Hamelin Pool Rd and then through the Hamelin Pool Telegraph Station grounds. Access is free.

• http://en.wikipedia.org/wiki/Hamelin Pool Marine Nature Reserve