Thessaloniki in Greece is famous for the place where apostle Paulo was directly engaged in the mission work of Christianity, as Epislte to the Tessalonians in the New Testament. Near Agios Dimitrios Church, there is a Roman agora (a market in ancient Rome) ruins where Paulo would have preached. Agios Dimitrios Church is a Greek Orthodox Church built in the 11th century,and is specified as one of the world's heritages. The Greek Orthodox Church remaining from the old days is characterized by the red brick walls and the chapel interior decorated with icons.