"Artvin" Artvin Ili by Fasulye

From the south of eastern Anatolia to the Black Sea there were a series of communications fortresses which could rapidly relay messages over hundreds of miles in ancient times. Messages were relayed optically with signal fires that could be seen (line-of-sight) from high points such that observers seeing a signal fire would respond by "passing along the message" to the next communications fortress beyond line of sight of the first.

Artvin is a city near the Black Sea that can be accessed by a north-south road from Erzurum Turkiye. This picture shows one of the communications fortresses going up the Oltu Gorge through which this road to Artvin passes.