No joke, Lake Hillier located on the largest Archipelago island in Australia is pepto-bismal pink. The lake is only a few steps away from the normal blue colored Southern Ocean. Scientists can’t actually figure out why the lake is so stubbornly pink. Despite their efforts, it refuses to turn blue, green, or even brown as a lake should be. Scientists estimate that the color is due to the mixture of sodium bicarbonate, or baking soda, and sea salt found in the lake.
Another hypothesis is that the pink color is due to red halophilic bacteria in the salt crusts. It is safe to swim in, though, as it is just another salt lake that happens to be pink. From above the lake appears a solid bubble gum pink, but the shoreline looks more like a clear pink hue is in the water. The shoreline is also covered in salt crust deposits.