Lake Hillier - The Strawberry Milk Lake In Western Australia
No-one knows for sure why is the lake pink. Scientists suspect that the color comes from a dye (red pigment beta carotene) created by green alga dunaliella salina halobacterium cutirubrum, halobacteria (names of bacteria), and high concentration of brine shrimp.
The color is permanent, so you can keep some inside water bottle and bring it back as souvenir.
I hope you like my choice of travel destination instead of cats for Caturday :p