This was in a giant cavern close to the end of our two-hour tour of the salt mine. I don't know exactly what this enormous structure was, but maybe it was holding up the ceiling. It was a bit unsettling to see all the cracked beams, with one even being held together by wire, but the tour guide had said they use soft wood in the mine so it can be heard creaking before it gives way. I guess hard timber would just shatter without warning.