ery significant thermal spa, water of Châtelguyon, known from the Romans, then it keep out of the limelight were given with the honour at the end of the 17th century. It was especially at the beginning of the 20th century that the station be developed. Thirty sources leave along Sardon. Water is characterized by their strong content magnesium chloride. They are richest in .Europe. Their temperature varies 27,5°C with 38°C.