Derbent

 city, UNESCO World Heritage Site

Derbent (Russian: Дербе́нт; Lezgian: Кьвевар, Цал; Azerbaijani: Дәрбәнд, romanized: Dərbənd; Avar: Дербенд), formerly romanized as Derbend, is a city in Dagestan, Russia, located on the Caspian Sea. It is the southernmost city in Russia, and it is the second-most important city of Dagestan. Derbent occupies the narrow gateway between the Caspian Sea and the Caucasus Mountains connecting the Eurasian Steppe to the north and the Iranian Plateau to the south; covering an area of 69.63 square kilometres (26.88 sq mi), with a population of roughly 120,000 residents. Derbent claims to be the oldest city in Russia, with historical documentation dating to the 8th century BC, making it one of the oldest continuously inhabited cities in the world. Due to its strategic location, over the course of history, the city changed ownership many times, particularly among the Persian, Arab, Mongol, Timurid, and Shirvan kingdoms. In the 19th century, the city passed from Persian into Russian hands by the Treaty of Gulistan of 1813.
Derbent is derived from Persian "Darband" (Persian: دربند, lit. 'Door/opening in a Barrier', from dar "door/gate" + band "barrier/dam", lit., "gate in the barrier"), referring to the eastern-most pass in the high Caucasus Mountains (whence the putative "barrier/dam") on the beaches of the Caspian Sea. (The other pass, the Darial Pass, is in the Central Caucasus Mountains, and likewise carries a Persian name, standing for "the Alan Pass/gate" – with the Alans being the modern Iranic Ossetians.) It is often identified with the Gates of Alexander, a legendary barrier supposedly built by Alexander the Great in the Caucasus. The Persian name for the city came into use at the end of the 5th or the beginning of the 6th century AD, when the city was re-established by Kavadh I of the Sassanid dynasty of Persia, but Derbent was probably already in the Sasanian sphere of influence as a result of the victory over the Parthians and the conquest of Caucasian Albania by Shapur I, the second shah of the Sassanid Persians. In Arabic texts the city was known as "Bāb al-Abwāb" (Arabic: بَاب ٱلْأَبْوَاب, lit. 'Gate of all Gates'), simply as "al-Bāb" (Arabic: ٱلْبَاب, lit. 'The Gate') or as "Bāb al-Hadid" (Arabic: بَاب ٱلْحَدِيد, lit. 'Gate of Iron').[16] A similar name meaning "Iron Gate" was used by Turkic peoples, in the form "Demirkapi".