Busby's Bore, Heritage tunnel and aqueduct in Surry Hills, Sydney, Australia.

Busby's Bore is a 3.6-kilometre tunnel cut through sandstone from Busby's Pond near the Lang Road entrance of Centennial Park to Hyde Park, near the Oxford Street entrance. It falls 53 centimetres end to end, and a line of pipe on trestles once carried its water to Park and Elizabeth Streets.

John Busby proposed in 1826 a tunnel to carry water from the Lachlan Swamps to Hyde Park; work began in September 1827 and was done by convicts in three eight-hour shifts. Water reached Hyde Park in 1830, though the bore was only completed in 1837, after quicksand in Moore Park forced a reroute. From 1844 reticulation pipes connected houses and public fountains.

Convict labourers dug the bore in three eight-hour shifts, up to 140 men at a time, often standing waist-deep in water. John Busby complained of their "vicious, drunken and idle habits" and of overseers filing false work returns. From 1844 reticulation pipes let houses connect and public fountains were established.

The tunnel system runs beneath active city streets and is not directly accessible to visitors today as it lies underground. Historical markers and information signs on the surface allow visitors to trace its route and significance.

The fall from the Lachlan Swamps end to Hyde Park is just 53 centimetres over 3.6 kilometres, so the water moved by gravity alone. Convict gangs of 50 to 140 men worked around the clock in three eight-hour shifts, keeping the tunnel from filling with groundwater.