Hotel trades off the Spa, but the bedroom maintainance is way off what I'd expect from a 5* hotel. Wardrobe sensor light sensor hanging from inside, meaning light permanently on and next to bed, incapable of sleeping. In room phone didn't work either, meaning a late night trip to reception in person to complain. Ended up having to move rooms but placed on the main road with crowds of people until 3am partying and shouting. Latter not hotel fault, but bizarre to have a room literally onto pavement with such a rowdy street. The toilet flush couldn't stop in new room. All in all a very disappointing stay - and lacking the other basics you expect of a 5* establishment. Robes thin, slippers cheap, no papers anywhere.
Would recommend saving the expense and booking somewhere cheaper and going tp the Thermae Baths instead if you really want to use the natural springs.