The history of Yoncalı hot springs dates back to about 800 years ago, to the Seljuk State. According to legend, during the Anatolian Seljuk State, the beautiful daughter of Sultan Alaeddin Keykubat II, Gülümser, caught a skin disease. In time, sores called boils covered her entire body. All the efforts of the doctors could not find a cure for this relentless disease. Gülümser's beautiful face and skin deteriorated day by day. Her hair fell out, and she became embarrassed to go out in public. The Sultan asked her father to send her to a place far from the people. Although Sultan Alaeddin Keykubat II did not want it, he fulfilled his daughter's wish and came to the area we call Yoncalı today, on the skirts of Kirazlı Mountain, with his guards, maids of honor and servants. Tents were set up and Gülümser Hatun began to live her destiny far from the people here. Days passed, one day while resting in his tent, he saw a mangy fox whose fur had fallen out and whose entire body was covered in boils, washing and rolling in a hole in the spring and muddy waters (swamp) every day. The fox came at the same time every day and repeated this process. The girl saw the fox getting better day by day, her boils falling out and her hair growing out. And she did the same thing on herself. The wounds and boils on her body scabbed over and fell out day by day. Her hair grew back, she regained her former beauty and health. A messenger was sent to her father, Sultan II. Alaeddin Keykubat, to inform him of the situation…

The Sultan came to Yoncalı with joy. When she saw with her own eyes that her daughter had regained her health, she had drums played and feasts given. She had a men's bathhouse with a large domed pool, a small women's bathhouse and a mosque built here so that others could also find healing. (1230) The legend that started centuries ago continues to come to life today with the Gülümser Hatun Thermal Facilities.