Mono Lake is a large, ancient saline lake located in eastern California, near the Sierra Nevada mountains. It is one of the oldest lakes in North America, estimated to be over 760,000 years old. The lake is known for its unique ecosystem, which supports various species of birds and brine shrimp, despite its high salinity and alkalinity. The lake features striking geological formations called tufa towers, which are created by the interaction of freshwater springs and alkaline lake water. Mono Lake is also an important site for environmental studies and conservation efforts, as it has faced challenges from water diversion and climate change.