<a href="https://en.wikipedia.org/wiki/Opal_Pool" class="extiw" title="en:Opal Pool">Opal Pool</a>, with Twin Buttes beyond, in the Midway Geyser Basin, Yellowstone National Park, Wyoming, USA.
<a href="//commons.wikimedia.org/wiki/User:Acroterion" title="User:Acroterion">Acroterion</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>