Balkan Mountains
The central Balkan Mountains rise above the plains of northern Bulgaria in a long chain of wooded slopes and exposed summits. Rivers including the Vit and Osam begin in these highlands and descend towards the Danube. Through the Troyan Pass, the Roman Via Traiana crossed the range between Lower Moesia and Thrace. Forts and road stations once watched the route as it climbed from the valleys towards the ridge.