Yalova Thermal Spas

Yalova Thermal Spas are located approximately 12 kilometers southwest of the city center of Yalova, in the southeastern part of Türkiye’s Marmara Region. The spas are situated within the boundaries of the Termal district, covering an area of 3,750 dunams of forested land, within a natural, archaeological and historical site. Designated as a Tourism Center in 1993 under Law No. 2634 on the Promotion of Tourism, this area is a significant destination for both individuals seeking therapeutic treatment and visitors coming for tourism and recreation. The site is regarded as one of the exemplary locations for the development of thermal tourism due to its climate characteristics, natural landscape, water quality and historical background.

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The historical origins of the Yalova Thermal Spas extend back to the Hellenistic and Roman periods. During the Roman and Byzantine eras, the area was frequently visited by the public, particularly after Istanbul was declared the capital. Its international recognition increased after it won the title of “best healing water” at an international competition held in Rome in 1911. Following the foundation of the Republic of Türkiye, as part of the modernization initiatives launched by Mustafa Kemal Atatürk in 1929, the Yalova Thermal Spas were restructured. In line with Atatürk’s vision of Yalova as “the city of the future’s waters,” foundations were laid for modern facilities, and the Yalova Thermal Hotel, opened in 1938, became the first modern thermal facility of the Republican era. Mustafa Kemal Atatürk was its first guest.

The Termal district lies within the morphologically rugged structure of the Armutlu Peninsula and has an elevation ranging between 200 and 700 meters. The area is carved by deep valleys such as İsmail Dere and Çağlayan Deresi. The region is situated along the North Anatolian Fault Zone, a geological feature that indicates the tectonic activity responsible for the formation of the thermal springs. Geologically, the area is composed of Paleozoic schists, crystalline limestones, Eocene sandstones and Neogene sediments. Quaternary alluviums represent the youngest geological units. These formations play a key role in giving the thermal waters their rich mineral and therapeutic properties.

The hot spring sources of the Yalova Thermal Spas primarily consist of three main sources: Esas Kaynak, Gözsuyu and Midesuyu. Their temperatures range between 54°C and 64°C, classifying them as hyperthermal (above 38°C). The pH values range from 7.65 to 7.75, while electrical conductivity (EC) values fall between 1864 and 1877 µmhos/cm. The waters, characterized by their composition rich in sodium, calcium, sulfate and chloride, belong to the category of therapeutic waters. Based on these properties, the spas are classified by the International Society of Medical Hydrology (ISMH) as hypotonic and therapeutic.

Analyses conducted according to drinking water standards have determined that the waters contain low levels of heavy metals (iron, manganese, copper, lead) and pollutants (nitrite, nitrate), posing no health risks. The hardness levels range between 36.72 and 38.74 French degrees, placing them in the “hard water” category. The absence of industrial activity and agricultural pollution in the vicinity of the sources contributes to the preservation of water purity.

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The Yalova Thermal Spas are not only an important center for health tourism but also for recreation and nature-based tourism activities. The region’s landscape, green spaces, walking trails and forested areas provide visitors with opportunities to immerse themselves in nature. Additionally, the construction of hotels and accommodation facilities in accordance with environmental planning principles supports the area’s tourism potential. In the 1930s, the spa area was planned and developed according to modern urban planning principles under a master plan prepared by Henri Prost.

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