The former name of the city of Sofia was "Serdika." Translated into English it would be, "Middle." This was a very good name for the city. It is in the middle of a large valley, so when you stand on the mountains and look at it, it is literally in the middle. It was also in the middle of the route from the east to the west. Rome lies to the west and Istanbul (formerly Constantinople) is in the east. To travel from one to the other by land would take you through the "Middle."
Sofia remains in the middle even today. Bulgaria borders a Middle-Eastern country (Turkey) and it is part of the European Union. It is between two worlds. It is in the middle. It is a poorer European country, yet it is still connected to Europe economically through its E.U. membership. It is in the middle.
The middle continues to be a good description for this city, and even for this country.