Do you happen to know when the air conditioning was added? I recall what seemed a very cold visit nearly two decades ago but couldn’t find any information online as to when the air conditioning was added.
Hmmmm I don't know the exact year - googling it isn't helpful either, I only found this page saying the AC system has been expanded in 2018[0] but I can't find the original date of installation.
[0] https://roszak.pl/klimatyzacja-dla-kopalni-soli-wieliczka/