These pale gray and ivory "tufa towers," located in California's Mono Lake, may look like eerie art instillations, but they occur naturally and are made of limestone. Check out more of these fantastical towers.
Tufa, the unusual rock formations that jut out of Mono Lake in California's Eastern Sierra, are famous for their otherworldly beauty. The greatest concentration of these unique "towers" is located at the south end of the lake. In the photo above, the moon rises over one of the dark ivory towers.
Made of limestone, tufa forms as a byproduct of the precipitation of carbonate minerals from surrounding water. When water from heated underwater hot springs rich in calcium meet with the carbonates in lake water, the result is calcium carbonate, also known as limestone.
The odd shapes that tufa take can sometimes resemble coral. Towers like these were once submerged, but gradually began to become visible as water was diverted into the Los Angeles Aqueduct and the surface level of Mono Lake fell.
The tufa towers are seen in this reflection in Mono Lake's calm waters. However, the water's serene surface is sometimes disturbed by circular wave patterns that are caused by bubbles from freshwater springs rising to the top.