The (, the longest river thar runs solely in
Bulgaria , and a right tributary of the
Danube .
The Iskar is formed by three rivers, the Cherni Iskar, Beli Iskar and Levi Iskar (known under the collective name ''Iskrove''), with the source being accepted to be the one of the Prav Iskar, a tributary of the Cherni Iskar. After rising in the north slopes of
Rila , it is used to form the
Iskar Dam — the largest in Bulgaria. The river runs near
Sofia and passes through a gorge in the
Balkan Mountains with beautiful rocky forms. It flows in the Danube near the village of
Gigen in
Pleven Province . The Iskar is the only river to take its source from southern Bulgaria and cross the Balkan Mountains to flow into the Danube.
The Iskar flows through seven provinces of Bulgaria — the capital city of
Sofia ,
Sofia Province ,
Pernik Province ,
Vratsa Province , Pleven Province and
Lovech Province .
In terms of geology, the Iskar is the oldest river in the
Balkans and also the only one to have preserved its original direction despite the significant geological changes in later stages.
