Apolinary Tarnawski (1851-1943), a Polish physician who was a pioneer of natural medicine and geriatrics in Poland, founded a private sanatorium in Kosovo. In 1871, he graduated from the gymnasium in Przemyśl, after which he began his medical studies at the Jagiellonian University in Kraków, from which he graduated in 1877. For the following years (until 1882), he worked as an auxiliary physician at the Lviv General Hospital, dealing with the wards of internal diseases, gynaecology, skin and venereal diseases, and surgery. He also worked as a spa doctor in Żegiestów and Morszyn, and then for several years was the district doctor in Borszczów and Jaworów. In 1891, he opened a natural cure facility in Kosovo in the Eastern Carpathians, consisting of three salt works with neo-Gothic halls, spacious terraces for lounging, swimming pools, solariums and bungalows for patients scattered around an extensive park. Initially, it treated a dozen or so patients, but over time, it became hugely popular due to its original therapy and effectiveness. In 1896, a vegetarian diet was introduced, further increasing the establishment's fame. Kosów became in the first half of the 20th century the second capital of Polish bohemia after Zakopane. From 1922, Tarnawski expanded the Kosów establishment and introduced new methods of treatment. He was also an active member of the board of directors of the National Association of Spas and Health Resorts in Lviv and the author of books, including "Objaśnienie sposobu leczenia w lecznicy..." (1900) and "O wartościach klimatu kosowskiego" (1938). He left behind the manuscript "Higiena starości" (Hygiene of old age), which made him a pioneer of geriatrics, and his last work "Catechizm Zdrowia dla Uchodźstwa Polskiego," which he compiled in Jerusalem at the end of his life.