IF YOU'VE ever wanted to explore Sydney's first water source, The Tank Stream, here's your chance.
Tours are planned for May 8 and 9, and entries in the ballot for the coveted places close at midnight on April 8.
This underground curiosity was a vital source of life for the First Fleeters and, before them, the First Australians.
Captain Arthur Phillip chose Circular Quay as the birthplace of the new colony, in part because of this freshwater stream, which ran into the harbour from a swamp at the western end of Hyde Park.
It served as the main fresh water supply for the first 40 years of the colony.
But by the early 1800s its waters were so polluted that the colonists had stopped drinking from them, and in time it became a sewer, still emptying into the harbour.
As the burgeoning city grew up around the stream, it was covered over with sandstone blocks.
Today, the Tank Stream lies underground - a stormwater channel managed by Sydney Water.
The Tank Stream tour costs $35 (general) and $30 for Sydney Living Museums members. A maximum of two tickets will be provided per winning entry.
Enter the ballot HERE
