Why: It's ancient and lunar. It impressed Mark Twain in the 19th century (he put it in his book "Roughing It") and Pink Floyd in the 20th (they put it on the sleeve of their album "Wish You Were Here").
What: Mono Lake goes back at least 760,000 years, covers about 70 square miles and feeds no rivers, which makes it salty and strange in many ways. The shoreline, more than 6,300 feet above sea level, is crawling with alkali flies, packed so densely that you may at first mistake them for a black-sand beach. In the water are legions of brine shrimp, fingernail-sized creatures that float at all depths. Protruding from the water are the tufa towers, which look like irradiated anthills but are really calcium-carbonate mounds formed by interaction of freshwater springs and alkaline lake water.
If there were a lake on the moon, I'm pretty sure it would look like this. (And if the lovers of the lake hadn't waged a sustained political fight to save it from the thirst of Los Angeles, it would probably be a smaller, sadder spectacle now.)