Lopan
The Loppan' River (Лопань) is a river that rises in Belgorod Oblast of Russia and flows across the Russian-Ukrainian border into Kharkiv Oblast where it joins the Udy River in Kharkiv. The river is 93 kilometres (58 mi) long. The Kharkiv River is one of its tributaries.
Coordinates: 50°30′N 36°21′E / 50.500°N 36.350°E
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