were shaped from a substance called travertine, which forms from the build-up of sediments of calcium carbonate deposited in water from hot springs. Then the calcium dioxide degasses and you are left with these beautiful terraces, with warm water flowing over them
Bungle Bungles, Australia
They are beehive shaped mounds with tiger striping caused by bacteria growing on the gray stripes and iron manganese on the red.
The Blue Grotto, Italy
The Blue Grotto in Capri is a gorgeous cave with a brilliant blue color to it due to two separate sources of light. One is tiny, the opening you can see in this picture which allows small rowboats in. The other opening is much larger and beneath the first, sending in rays of light into the cave from below
phenomenon occurs at Racetrack Playa, Death Valley
The stones travel long distances without any human or animal help
making a trail or groove in the rock surface as they travel