Do you know that Sofia is the second oldest city in Europe, founded 7, 000 years ago by the Thracian tribe Serdi- What have Sofia to do with Roman provinces- Through the ages, the city played an important role as a trading center in the Byzantine and Bulgarian Empires. When was Sofia the center of Rumelia province- A local charismatic guide will reveal the secrets and interesting facts about the architectural styles of the compact city center, Boyana Church and the National History Museum - one of the largest in the Balkans.