It's located on the western shore of the Caspian Sea at the southeast extremity of the Lesser Caucasus Mountains
THE ELBURZ MOUNTAINS, ON THE CASPIAN SEA'S SOUTH 
SHORE IN... [DOC] [TLE] Caucasus | region and mountains, Eurasia | Britannica.com [PAR] May 20, 2015 ... Mountain system and region lying between the Black Sea (west) and the Caspian 
... the Hittite name for a people living on the southern shore of the Black Sea.