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 Sulis crossing point of their road, they would have been attracted by the large natural hot spring which had been a shrine of the Celtic Brythons, dedicated to their goddess, Sulis. This spring is a natural mineral spring found in the valley of the Avon River in Southwest England, it is the only spring in Britain officially designated as hot. The name is Latin for "the waters of Sulis." The Romans identified the goddess with their goddess Minerva and encouraged her worship. The similarities between Minerva and Sulis helped the Celts adapt to Roman culture. The spring was built up into