Aquae Calidae, Bulgaria Prista on the Danube. Near the baths a road station (statio milliaria) was created with the name Aquae Calidae. The Sanctuary of the Three Nymphs continued to exist next to the station and the Baths, and became known as the Nymphaeum of Anchialos. Under Septimius Severus in 209-211 three years of games and celebrations under the name of Severia Nymphaea took place in the baths. Games also took place in Aquae Calidae under the emperors Geta and Caracalla. Jordanes, who lived in the 6th century, described in his work Getica the incursions of Gothic tribes on the southern Black Sea
Aphanizomenon flos-aquae toxic chemicals released when cells die. Once released (lysed), and ingested, these toxins can damage liver and nerve tissues in mammals. In areas where water quality is not closely monitored, the World Health Organization has assessed toxic algae as a health risk, citing the production of anatoxin-a, saxitoxins, and cylindrospermopsin. Dogs have been reported to have become ill or have fatal reactions after swimming in rivers and lakes containing toxic "A. flos-aquae". Microcystin toxin has been found in all 16 samples of "A. flos-aquae" products sold as food supplements in Germany and Switzerland, originating from Lake Klamath: 10 of 16