Inside a old quarry, not in use and not for public..
entered this quarry thrue a collapsed pothole.
the tunnel system would be 75 to 200 km in lenght, and dates back to 1400, amazing to see paintings from 1400 / 1500.
going inside from 35c outside to 11c inside.
walked about 6 to 7 hours inside.
I did not use flash on camera, but painted it in with a flashlight.