Inaugurated in August 1902, the institute of hydrotherapy is considered to be the best of its kind. Open from 15 May to 15 October, it administers 1,200 treatments a day: baths, showers, massages, and electrical and mechanical treatments. Architect Ernest Brunnarius designed an impressive building: 68 m long and 25 m high, topped with a 30-m dome on a square base. Along the partially tiled façade, the ramps lead to a monumental entrance framed by bell towers. Under the porch, two paintings by Jean Benderly depict water. Listed as a historical monument, the building was extensively renovated from 2004 to 2006. Renamed the "Palais Lumière", it now holds a multi-media library, exhibition rooms and a convention centre.

- April 19, 2025 to January 4, 2026
Exhibition of a selection of more than three hundred works drawn from a private collection of nearly five thousand paintings, drawings, watercolors, prints, posters, books and illustrated magazines, by recognized artists or to be discovered.

Guided tour (in french only) every day at 2:30 p.m.
Little games at Palais Lumière for children between 6 and 12 years : a booklet with little games for a visit of the exhibition is available at the reception.