One of the most ancient cities in Europe and among the best cities to visit in Bulgaria, Plovdiv surprises visitors with its diversity. Located in southern Bulgaria, Plovdiv is like an open-air museum of Bulgaria’s history. Plovdiv used to be one of the major cities in the Roman Empire. Today, you can visit the Roman Amphitheater, which still functions as an open-air theater, the Roman Stadium, the Roman Forum, and the Eirene Residence. You’ll get a totally different vibe from the Old Town which has cobblestone streets and colorful National Revival houses, most of which have been turned into museums. For beautiful views of the city, climb on one of the seven hills on which the city was built. Ancient Plovdiv is on the Tentative List of UNESCO World Heritage Sites. 2019 will be a great year to visit Plovdiv because it will be the European Capital of Culture.