Hisarya, known as 'Sources des Empereurs' (Emperors' Springs) for its long history of aristocratic patronage, is a historic Bulgarian spa city in the Thracian Valley whose fluoride and radon-bearing mineral springs have been used since Thracian times and extensively developed during the Roman Empire as Augusta. The Roman emperor Diocletian reportedly valued Hisarya's waters, and the well-preserved Roman fortress walls still encircling the town give it a distinctive archaeological character unique among Bulgarian spa destinations. Hisarya's twenty-two mineral springs, set within an elegant park landscape of colonnades and fountains, make it Bulgaria's most historically rich thermal bathing destination.
Insider tip — Hisarya, known as Diocletianopolis in Roman times, has been a thermal resort for over two millennia, and its nickname 'Sources des Empereurs' reflects the imperial favour it once enjoyed. The warm fluoride-rich waters bubble up inside well-preserved Roman ruins, giving the town a layered archaeological atmosphere unlike most European spas. Modern balneology centres sit alongside crumbling Roman walls and a 16-hectare park of rose gardens and mineral fountains. Visit in late May when Bulgaria's rose harvest season fills the surrounding Thracian plains with fragrance.
