Since ancient times, Jews have lived in what is now Bulgaria, and historical records suggest there was a thriving community of Byzantine Jews there in the Middle Ages. Ashkenazi Jews didn’t settle in the country until the 13th century; at the end the 15th, the Sephardim who eventually came to predominate began to arrive. Yet no archaeological remains of medieval Bulgarian Jewy have been found—that is, until Mirko Robov began excavating what he had assumed to be a church. Amanda Borschel-Dan writes:
The [supposed] Jewish house of worship was discovered on the outskirts of a medieval fortress complex located on Trapezitsa Hill [in the medieval capital of Tarnovgrad]. It is a large building that was built during the 1240s and survived until the fall of Tarnovgrad during the Ottoman conquest in 1393, when the town was completely razed. . . .
Bulgaria boasts a 2,000-year-old Jewish community, members of which have been documented to have lived in a Jewish quarter on the Trapezitsa Hill during the Middle Ages. If confirmed as a synagogue after further research, this would be the only one from Bulgaria during this era, and one of only a handful that have been discovered throughout the continent.
“This new-found building is not a church, because it’s characterized by different planning and construction,” said Robov. “It’s coated from the inside, but there are no wall paintings. This is why I connect the building with the religious practices of a different ethnic group.” Robov explained that all of the place names that are connected with the city’s medieval Jewish population are found in areas on or around Trapezitsa Hill. These include a Jewish quarter, a Jewish graveyard at the northwestern foot of the hill, and an area on the southwestern foot called Chifutluk.
Read more on Times of Israel: https://www.timesofisrael.com/odd-13th-century-bulgarian-worship-hall-may-be-countrys-sole-medieval-synagogue/