It is connected by rail with the south Russian railway system at Beslan, the junction for Vladikavkaz (400 m.), via Derbent and Petrovsk, with Batum (560 m.) and Poti (536 m.) on the Black Sea via Tiflis.
It is in this valley that the principal towns (except Vladikavkaz at the north foot of the Caucasus) of Caucasia are situated, namely, Baku (179,133 inhabitants in 1900), Tiflis (160,645 in 1897), Kutais (32,492), and the two Black Sea ports of Batum (28,512) and Poti (7666).
The exports through the Black Sea ports of Batum, Poti and Novo-rossiysk average in value a little over £ro,000,000 annually, though showing a tendency to increase slightly.
This railway, together with the driving roads over the Caucasus mountains via the Mamison pass (the Ossetic military road) and the Darial pass (the Georgian military road), and the route across the Black Sea to Poti or Batum are the chief means of communication between southern Russia and Transcaucasia.
Baku and Batum (also Poti) are connected by another main line, 560 m.