Lanzarote

You can see how deep it is down there. I think it was a twenty foot drop-off and we were in the upper chamber. But we looked over the edge. I couldn't see him. Neither could the other people around me. Then BAM!!!!
A crash exploded the stillness. After the shock of it, we looked again and realized that we had been splashed with water and there were ripples in a tiny, little pool in front of us. It was about 2 inches deep.
Apparently, because there's black sand on the bottom, when you shine light on it and it's perfectly still, it creates a mirror reflection. Which, when you're walking up to it, looks like two chambers, an upper level and a lower level. It honestly did. I was fooled up to the discovery. And even after the pool quieted down again, it was hard not to be fooled. It was really cool. Michael took an excellent picture of the effect.