Ancient City of Nessebar, Bulgaria At the crossroads of culture, Nessebar was a starting line for many European concepts we take for granted today. Originally a Thracian settlement, it became a Greek colony at the beginning of the 6th century BC. But the peninsular town possesses more than the remains of an assortment of iconic and historic eras. This hub on the Black Sea changed the world because the very concept of money was invented here. Nessebar was once an important trading city and part of the Delian League: an alliance of ancient Greek states. During the centuries to follow, it remained a strategic nexus for the cultures and epochs that passed through this pivotal place. Today, you'll find the remnants of these eras in the form of buildings from the Middle Ages and Byzantine Empires.