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 Aquae Flaviae Aquae Flaviae (or "Aquæ Flaviæ") is the ancient Roman city and former bishopric (now a Latin Catholic titular see) of Chaves, a municipality in the Portuguese district of Vila Real. The northwest peninsular region is an area of hot springs and Roman settlements linked to the exploitation of valuable natural resources. Aquae Flaviae was the principal "municipium civitas" in the northwest (from epigraphic findings) implanted in the Trás-os-Montes, on a small hill on the banks of the River Tâmega, in the Roman province of "Gallaecia". This was a fertile area, where hot springs abound, in addition to a