Aquae Calidae, Bulgaria Aquae Calidae, Bulgaria Aquae Calidae (Latin for warm waters), also known as Therma and Thermopolis in the Middle Ages, was an ancient town in Thrace located in the territory of today's Bulgarian port city of Burgas. It was built around thermal baths using the hot springs and became one of the most important spa centres of ancient times. The site and baths of Aquae Calidae have been visited in the course of history by several important rulers from Philip II of Macedon to the Eastern Roman emperors Justinian I and Constantine IV, the Bulgarian ruler Terwel and the Ottoman Sultan
Aquae Iasae part of the Roman settlement was located on the highest terrace of the hill Varaždin spa, today the park and archaeological site. The residential part of "Aquae Iasae" was on the terraces that descend to the foot of the hill in the foothills of the craft-established commercial and trade show facilities. At the end of 3rd century AD Aquae Iasae were ravaged during the incursion of the Goths, then in the beginning of the 4th century the "thermae" were restored by Emperor Constantine. The resort was completely ruined and deserted in the 4th century during the invasions of the Migration