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 Flaviae of Trajan over the Tâmega River, whose existence marked a period of exceptional development of the city. Functioning as a crossroads, it controlled the routes to the mining districts. The remains of two epigraphic inscriptions are located on the bridge, commemorating the construction or remodelling by Emperor Trajan, as well as another that aroused various interpretations, the "Padrão dos Povos". The "Padrão dos Povos" mentions the civitates dependant of Aquae Flaviae: Aquiflavienses, Avobrigenses, Bibali, Coelerni, Equaesi, Interamici, Limici, Naebisoci, Querquerni and Tamagani, as well as the Roman Legio VII Gemina Felix legion. Aquae Flaviae was founded by Rome, although the