Launceston's impressive Cataract Gorge. Specifically, the South Esk river thundering beneath the suspension foot bridge and into the Basin. People kayak on this river, though it's gathered a reputation for putting people in hospital with broken bones.
Cataract Cruises chugs beneath King's bridge into the Gorge. This map gives you an idea where it is. It's the Trevallyn Road bridge, built in 1903.
Taken from King's Bridge, looking into the Gorge.
A good overview of the Cataract Gorge Basin. William Collins explored the area in 1804 and described its natural beauty as unsurpassed in the world.
Here's a good shot of the Basin, and the public pools. The water is reasonably high in this shot, flooding some paths. When the flooding gets serious, such as in the first image on this page, these pools are well underwater.
The Gorge in full flood Winter 2009! Somewhere around 100 cubic meters per second of water thundering past there. The river level rose to 5.5 metres, apparently.