A rare gold coin from the time of the Byzantine Emperor Phocas was discovered during excavations at Rusokastro Fortress, which is located on a hill near Zhelyazovo village, in Burgas district in southeastern Bulgaria, quoted by the Bulgarian National Television. 

The find proves that the fortress was active in the 6th century, the archaeological team commented.

This is the first and only coin ever found since the time of Emperor Phocas's rule. The discovery proves conclusively that the Rusokastro Fortress was actively used during the first period of the consolidation of the rock hill - in the 6th century and the beginning of the 7th century when it was abandoned.

Milen Nikolov, Director of the History Musemum in Bourgas and head of the excavations explained that the gold Early Byzantine coins are two types - tremissis and solid, and the latest find was a solid coin.It weighs 4grams and a half and is the biggest denomination in the Byzantine coinage."

The extensive studies of the Rusokastro Fortress aim at its restoration and turn it into a site of cultural and historical tourism.

The fortress stretches over an area of 52 decares, making it the largest medieval fortress in South Bulgaria, similar in size to Tsarevets, Trapezitsa, Cherven and Kaliakra.

The walls are more than 5 meters high. Excavations of the site are funded by the Ministry of Culture and the National Museum of History.