Lake McDonnell is situated on the Eyre Peninsula in Southern Australia (SA). The pink colour of one segment of the lake is caused by an algae that feeds off salt and secretes a red pigment that gives the water its salmon hue. There is a large gypsum mine close by and it is stockpiled and left to sit for several years allowing the salt to leach out.

To the left of the causeway is the green lake and in the distance is the blue lake. And further beyond is the Southern Ocean at Point Sinclair and Cactus Beach a legendary surf spot.