Looking like a futuristic cathedral, Europe's largest spa complex is a wonderful place for some soothing relaxation after exertions in the mountains. Fed by 70°C springs, its heart is a 600-sq-m lagoon kept at a constant 32°C. A series of other pools, plus Turkish baths, saunas, spas and hydromassage, are all covered by the three-hour entrance ticket.
You can sign on for a whole range of extras, including Thai massages, citrus body scrubs and the enticing adults-only Inúu space.
Caldea is 800m northeast (upstream) from central Plaça de la Rotonda.