Founded 2300 years ago Thessaloniki is the second largest city and port in modern Greece and could literally be called an open-air museum. Take a guided tour of one of the most important centres of Greece and visit the fortress walls and the Byzantine emperor's tomb, the Roman Forum and the triumphal arch of Galerius, the church of St. Demetrius of Thessaloniki, the famous White Tower and the other landmarks of the city.