We know it today as The Tank Stream – an underground curiosity – but it 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 running right into the harbour from a swamp at the western end of Hyde Park. Having supplied fresh water and fish to the original Gadigal People for tens of thousands of years, it would serve as the main fresh water supply for the first 40 years of Sydney’s European life.

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.

This tour, available only twice a year, takes you through 60 metres of this state heritage-listed tunnel built by convicts and stonemasons. Admission on the tour is by ballot registration only. Winners of the ballot have the opportunity to purchase up to two tickets for their tour.

In partnership with Sydney Water.