The Ancient City of Nessebar is an outstanding testimony of multilayered cultural and historical heritage. It is a place where many civilizations left their tangible traces: archaeological structures from the Second millennium BC, a Greek Black Sea colony with surviving remains of fortifications, a Hellenistic villa and religious buildings from the Antiquity, preserved churches (in some of them preserved only parts of archaeological structures) from the Middle Ages. Nessebar has demonstrated its historical importance as a frontier city on numerous occasions. Having been a remarkable spiritual centre of Christianity for a thousand years, today it is a developing and vibrant urban organism.