This popular travellers' spot used to serve as a healing temple in the past. Hippocrates is believed to have worked here.
Wikipedia https://uk.wikipedia.org/wiki/Асклепіон
More information at Kosinfo.gr http://www.kosinfo.gr/sightseeing/asclepion
Address 85300, Greece
Coordinates 36°52'32.776" N 27°15'26.314" E