Answered my own question
I found this in their newsletter:
GB Spa Indoor Pool and Thermal Suite
Indoor pool with ozone-and-mineral water and hydro-jet massage.
Thermal suite: Herbal Steam Bath, Amethyst Grotto, Laconium, and Sauna
plus an Ice Fountain, Reflexology Foot Massage and Lifestyle Showers.
Entrance is free for hotel guests; €45 with a spa treatment starting
from €50 for external patrons.