city and administrative centre of Balkan oblast (province), western Turkmenistan, at the southern foot of the Bolshoy (Great) Balkhan Ridge. Its name means “oil mountain,” and it is the headquarters of the Turkmen oil industry. Nebitdag grew up on the Transcaspian Railway after large oil deposits had been discovered in the area in the early 1930s; it became a city in 1946. It has been carefully planned, with much greenery to mitigate the effects of the surrounding desert. Pop. (1997 est.) 87,800.