The bad thing first, because it was unfortunately on my mind as we left Karlovy Vary. Upon check-out we were told we had to pay an extra charge of CZK450 for using the sauna. We protested that we had not been told about this charge at any point, and the clerk apologised for that, but still brushed it off by saying "it's only 15 Euros". As we needed to get to our transport we didn't have time to argue, so we paid and left. This really feels like a rip-off charge as it is not mentioned in any of the hotel booklets; in fact it says that the swimming pool and sauna is free to use for guests. The reason that was given for the charge was that no-one else was using the sauna and that it therefore had to be warmed up only for us, but I do not think that is a valid reason, especially not for a 4-star hotel. It is also worth mentioning that the hot tub was only functional on one of our three days in the hotel. Apart from that, the hotel is clean, in a nice location and has an alright breakfast buffet.