I was booked into the Auschwitz Birkenau museum in Krakow. On the day I was to go, it was cancelled. After I received notification from Flight Centre about the cancellation there was no reason given. After explaining that I was totally devastated after specifically booking to go to Krakow Poland, I was told that tours booked to Auschwitz, often get cancelled because some tour operators do not meet strict guidelines enforced by the Auschwitz Museum, and there are arguments between the two who want to arrange their own guides. I was fortunate to come across a legitimate operator in Old Town Centre in Krakow who said he had available tickets for the next day. We were thoroughly surprised and immediately booked. The operator came on the time made, and we finally got to see Auschwitz, no thanks to Viator.