Susan Polgar's blog has a report of a blitz tournament that was played in Carlsbad Caverns in the United States. From the photos it looks as the games were played deep underground, and lamps had to be used to illuminate the boards.
When I was younger I did a little bit of spelunking, although chess was one thing I didn't do underground. I've crawled, swam and got lost in caves, and have even done some abseiling. Maybe next years trip to Blayney will involve a detour to Abercrombie Caves, with a few games of blitz to mark the occasion.