An incorrect question...How can one country exist without a boundary? Is it just for making fun by asking such question?Bulgaria's boundaries: North- Romania (mainly by Danube river, West- Serbia and...
The river Danube and the South Dobrogea.
The Balkan Mountains forms Bulgaria's northern boundary with Romania. The river Danube and the South Dobrogea (from Vama veche to Ostrov in Romania).
The Danube
landscape features