Thermal spa architecture: 10 must-see projects

Le Havre was a port even before it was a city, keeping pace with the changes brought about by the evolution of maritime trade. With technological progress and the unstoppable increase in trade volumes, the port has had to build new infrastructure adapted to new needs. The land thus freed has been returned to the city and has opened up to new developments that have revitalised city life. Les Bains des Docks, the new public baths designed by Jean Nouvel and inaugurated in 2008, is one such space. Inspired by the spontaneous formation of natural water pools in the rock, the baths consist of three main entities: a heated outdoor sports pool of Olympic size at fifty-one by twenty-one metres, an indoor and outdoor leisure pool and a spa, all connected by canals and with a water slide. Continuity in the architectural treatment is ensured between the interior and the outdoor lagoon, with the opening, during the summer season, of the massive facades towards these areas.

Built above the thermal springs of the Canton of Graubünden in Switzerland, the Therme Vals include a hotel and spa, in a continuous sensory experience typical of Peter Zumthor's architecture. The architect, working with the natural surroundings, worked the building like a large volume of stone leaning against the slope, "hollowed out" inside in a spatial continuum fed by cavities. The internal and external wall surfaces of the parallelepiped volume of the spa are warped thanks to the uniformly dense stratification of the local natural stone, a siliceous and schistose quartzite, quarried in the valley.

Smolenicky & Partner Architektur designed the Tamina Thermal Baths in Zurich, an architecture characterized by high shaped columns that frame the rooms with oval openings at every step. The project, the result of a two-stage competition in 2003, includes thermal baths with indoor pool, large sauna area, shops and restaurant, with a result explicitly conceived as part of the grand hotel culture. For this reason the volume of the building has a monumental character, to stand out as an institution on a par with the other buildings of the resort. At the same time, the spa is intended to relativize the almost "urban" stone character of the thermal spring hall. This explains the pure white wood of the spa, giving it the character of a pavilion in the architecture of a historic resort. Structurally, however, the building can be more or less seen as a forest, created by columns instead of trees, with a total of 115 supports using the wood of 2,200 fir trees.

Matteo Thun's transparent design in Merano's historic spa creates a continuum, with the design of a huge glass cube, between inside and outside, illuminated by a flow of natural light during the day and large globes at night, reflecting their light on the large coloured discs that freely rotate above the pools. Swimmers can swim directly the largest of the twelve indoor pools to the thirteen outdoor pools. Natural stone and wooden materials create continuity between the structures, pools, fitness equipment and indoor relaxation loungers and the like. outdoor facilities, continuing seamlessly into the park and wider surroundings.

The site given for the construction of the new structure of these baths is a place that is characterized as a park and free space at the base of the mountain behind. Botta, in this project, aims to build without building, affirming the presence of the new through small emerging bodies, almost like leaves, and leave the large volume underground with the functional program. The covering of the underground spaces is thus transformed into a stage marked by geometric plant presences, signs that also contribute to the lighting of the spaces below. The interior space is presented as a single large terraced environment that follows the slope to limit the excavation work, with a plan design is designed modularly, so as to allow maximum flexibility in the dislocation of the various functions.

Eskisehir has a rich and stratified historical background, and the Odunpazari region, in particular, has great tourist potential with its intact historical structure. The project was strongly influenced and inspired by Eskisehir's thermal water resources, and is therefore a modern interpretation of Odunpazari's vernacular architecture and existing historical structure. The complex includes a spa and wellness centre in the centre, and residential units on the perimeter. The construction also touches on aspects of sustainable design using wind and solar energy, and geothermal energy, used not only in spas, but also for space heating during the cold seasons, through a system of geothermal heat pumps.

The project of the Förena Cité thermale, at the foot of Mont-Saint-Bruno in southern Quebec, was the result, right from the concept phase, of a desire to create a spa experience inspired by European experiences, with direct quotations to Icelandic, German and Russian establishments. Following, therefore, the desire to infuse different themes in the architecture of the premises without falling into pastiche, the architects were led to create three separate pavilions that are presented in a coherent way in a micro-village organized around an outdoor courtyard. Of course, the big attraction here is the huge Icelandic-inspired outdoor thermal pool, dotted with imposing black rocks and surrounded by Canadian forests.

Shigeru Ban, on the other hand, is the author of this unusual example of public thermal baths, located inside Onagawa train station, previously destroyed by the devastating earthquake of 2011. The terminus connects the community to the surrounding region and aims to be the focal point of the city's redevelopment. Before the earthquake there was a public thermal spring located next to the train station. It was a popular place where locals came to bathe, dine nearby and then return for another bath before going home to sleep. Ban incorporated this bath into the design of the new station, allowing the entire second floor to be dedicated to the thermal spring.

The spa resort is located in Tengchong Mountain, Yunnan Province, China, near Yunfengshan Mountain, known as a sacred place of Taoism. So the architects have arranged the various buildings that make up the resort - more than 400 independent villas and eight communal structures scattered over an area of about 50,000 mw dot the valley discreetly - so as to follow the current of the "spirit" coming down from the mountain. The resort camouflages itself among the folds of the mountain thanks to the local rocks used for the floors of the lanes, walls and roofs of the buildings, creating a covering pattern in harmony with the natural elements, using six types of natural stone and different colour shades - grey, brown, beige and ochre.

The project consists in setting up a wooden structure on the hot water springs that flow naturally in an almost inaccessible ravine, in the middle of the native forests of the Villarrica Volcano National Park. To bathe at ease, 20 wells have been dug along the 450 meters of the gorge, in the midst of brutal nature, which can be reached by a wooden walkway, a continuous ramp without steps, which allows you to walk safely along the gorge. The geometry of the path and the small pavilions, which house the various services, highlights what is natural and separates it from what is built, while the wooden walkways, coloured deep red, stand out against the background of the landscape.