In 1910-1911, Burgas Municipality performed cleaning of the mineral spring in Burgas Mineral Baths at the place of the ancient Aquae Calidae. During the works two pools revealed, inside which were found around 4000 coins of bronze and silver, and a huge amount of other artifacts - rings, gems from rings, crosses, combs, hair pins made of bone, fibula and many others.
Today, all these findings are kept in the National Archaeological Institute with Museum in Sofia.
The findings from the pools strike with its representativeness and high value. Among them are two extremely important artefacts - two gold ring with inscriptions that belonged to the representatives of the highest aristocratic circles in Byzantium and the Bulgarian kingdom.
The rings were cast from solid gold with 23 carats sample. The first weights 28 grams. Its front plate is round with an inscription. The ring piece is attached to it by two exquisitely crafted lion heads. On the plate served as a stamp, is engraved in negative a Cyrillic inscription that reads: "PETER EPIKERNIY cousin to the Tsar" . The ring dates from the early 14th century and it was personal property of the ruler's cousin and epikerniy named Peter, who probably cast it in the hot springs as a gift for his healing with the help of the mineral water.
The title epikerniy was awarded to people closest to the tsar's party, often relatives. Basically this was the king's personal cup-bearer, who was one of the most trusted aristocrats of the ruler.
The second ring weighs 30 grams. The ring's plate, which was used also as a stamp, is octagonal and goes into the ring through tripartite shaped shoulders. Under the plate there are 8 slots for enamel, similar to the external sides of the ring. The ring dates back to the 13th - beginning of the 14th century.
The plate of the ring is engraved with a cruciform monogram that reads "NIKHFOPOC" , which means its holder's name was Nikifor. He was apparently very wealthy or a senior Byzantine aristocrat who cast the ring as a vow in the springs as a gratitude for being cured by the mineral water of Aquae Calidae.
Both rings were used also as stamps, ie with them their holders were stamping their correspondence.