Salt Lake Eyre
This photo was taken at salt lake Eyre which is the biggest lake australias, when it's filled with water. In the wet season it can expand up to 9600 km^2 with a deepness of 4m. That's the reason why you can see the foot steps in the lake, it is just a few cm deep.
It is really impressive to see such a huge, flat, puddle with it's water to the horizon, in the middle of the desert.