"Wild" Cave in Craters of the Moon
This is the inside of Boy Scout Cave in Craters of the Moon NM. I'm standing on ice about 20 feet below the surface, looking out at the 90 degree (F) surface.
As you can tell from the ropes in the foreground, the cave has been slightly "improved" (these ropes are the only "improvement" and are there to steer visitors down an easier scramble to my right).