About 97 miles by road. Estimated journey time by road about 2hrs 30mins. (Information from RAC Routefinder). (In 2000 I did the journey by rail, and it also took about 2hrs 30 mins. I note that the question is included in an Air Travel category. I honestly don't think it's worth flying between the two places).
Sofia, Bourgas, Plovdiv, Varna
Sofia, Plovdiv, Burgas, Varna, Ruse
Sofia, Plovdiv, Varna, Burgas, Veliko Tyrnovo
Sofia, Plovdiv, Varna, Bourgas, Blagoevgrad, Pleven etc.
about 190km
Major cities are Sofia, Plovdiv, Varna, Bourgas, Rousse, Stara Zagora, Veliko Turnovo...
That would be LUDOGORETS, LEVSKI SOFIA and CSKA SOFIA who are 1st 2nd and 3rd in the respective order they appear.
The country bordered on the north by Moldova is Romania. You can choose any city in Romania for this, like the capital: Bucharest.
London England to Sofia Bulgaria distance is: 2437 kilometers
total driving distance from Sofia, Bulgaria to Istanbul, Turkey is 350 miles or 563 kilometers.
Capital=SofiaOther Cities=Rousse, Pleven, Silistra, Plovdiv, Varra, Shumen, Veliko Turnovo, Bourgas, Kazanlak, Balchik, Kiten, Primorsko, Sozopol, Nessebar, Ravda, Sveti, Vlas, Ahtopool, Kavarria, Obzar, Sinemorets
1. Sofia 2. Plovdiv 3. Varna 4. Bourgas 5. Rousse (controversial)