Luchon was named after Ilixon, a Roman goddess of water ... Needless to say how important the water is in the life of the region!
Also, the town of Bagneres de Luchon is famous for its thermal springs and its Vaporarium (the only natural steam room in Europe!) combining both fun and well beeing. Pools are accessible for people with reduced mobility.
The valley of Loudenvielle focuses more on the thermo-playfulness (hot tubs, SPA, upstream swimming, water games).