Other Placenames
There are a number of ancient placenames from other languages, including Thracian or Dacian, such as Plovdiv, derived from Pulpudeva (itself derived from Philipoppolis), German and Celtic, such as Vidin from Dunonia and Bononia.
The placename Varna of the non-metathesized group CorC bears witness of Old Bulgarian's preliterate period - or perhaps stemming from a more ancient Proto-Indo-European root.
Read more about this topic: Bulgarian Placename Etymology