This story appears in the December 2018 issue of National Geographic magazine ... ecosystem of Yellowstone Lake to explore unique spires formed by dormant hydrothermal vents thousands of years ...

This story appears in the November 2009 issue of National Geographic magazine ... All around, jagged spires and flutes rose like the towers of some Gothic cathedral, silent and empty.

Carved from ancient volcanic rock formations over millions of years, these towering spires in Cappadocia, reaching up to 130 ...