The Columbia Encyclopedia, Sixth Edition. 2001-07.
Iskr
(s´kr) (KEY) , river, c.250 mi (400 km) long, rising in the Rhodope Mts., W Bulgaria, and flowing generally NE past Sofia and through the Balkan Mts. to the Danube River. The gorge of the Iskr is one of the chief passes through the Balkans.