The photo above showing an interior area of Crystal Cave was taken in Sequoia National Park on the western flank of the Sierra Nevada Range in California. Crystal Cave is one of 240 known caves found within the park. Photographer: Nel Graham
It’s a classic solution cave; created in carbonate and sulfate rocks when slow moving groundwater dissolves the rock, in this case marble, to form irregular passages and in some instances, cavernous openings. In the portion of the cave shown here, flowstones dominate from the ceiling to the floor. Though not as large as some of the more famous caves in the world, Crystal Cave is a welcome respite on hot summer days as its interior temperature stays at approximately 48 F (9 C) year round. It’s open to the public from mid May to mid October.