Cave?
One of my very favorite childhood memories was a field trip we took to an emerald mine when I was in fifth grade. We left before the sun was even fully up, and rode several hours into the mountains. I don’t remember much of the day in general—bits and pieces from lunch, the gift shop, panning for emerald fragments in the stream, but the one thing I remember most clearly was the tour through the mines. There was a portion of the tour in particular where you walked out onto a glass floor and there were floodlights underneath illuminating a flooded section of the cave below. They turned out the lights above and had us all look down while the guide told us just how deep it went, and how big the “room” actually was. The water was so crystal clear, but got bluer and greener the deeper it went.
On another note, I’ve lived an hour from a gold-rush era gold mine my whole life.
