Sept. 5, 2010 - Mono Lake, California, U.S. -Tufa towers are seen along the shore of Mono Lake near Lee Vining, California. "Tufa towers," are calcium-carbonate spires and knobs formed by interaction of freshwater springs and alkaline lake water. Mono Lake is a majestic body of water covering about 70 square miles. It is an ancient lake, over 1 million years old -- one of the oldest lakes in North America. It has no outlet and no fish; instead it is home to trillions of brine shrimp and alkali flies. (Photo by Alan Greth/ZUMA Press)