Yettie Road, Williamstown, SA 5351

For those who don't know about it, its a well hidden secret in South Australia.

The fascinating Whispering Wall has unique acoustic effects that allow you to whisper at one end, and have a friend hear your whisper more than 100 metres away. Children in particular love visiting the wall and testing its abilities.

The Whispering Wall is in fact a retaining wall for the Barossa Reservoir and provides a scenic view of the reservoir. A collection of water supply heritage items is also on display.