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
Albulae Aquae fact." Albulae Aquae Albulae Aquae ("The White Water") is a group of springs located West of Tivoli in Italy. The springs' water is bluish, strongly impregnated with sulphur and carbonate of lime, and rises at a temperature of about . The remains of a Roman thermal establishment exist near the principal spring, the so-called Lago della Regina, which is continually diminishing in size owing to deposits left by the water. Dedicatory inscriptions in honour of the waters have been found at the site. It is mentioned briefly by many ancient authors, among them, Virgil, Vitruvius, Isidore of Seville, and Pliny