Shirvan (from Persian: شیروان, romanized: Shirvān; Azerbaijani: Şirvan; Tat: Şirvan) is a historical region in the eastern Caucasus, as known in both pre-Islamic Sasanian and Islamic times. Today, the region is an industrially and agriculturally developed part of the Republic of Azerbaijan that stretches between the western shores of the Caspian Sea and the Kura River, centered on the Shirvan Plain.