There are several archaeological sites near Gorgan, including
Tureng Tepe and
Shah Tepe, in which remains dating from the
Neolithic and
Chalcolithic eras. Some other important Neolithic sites in the area are
Yarim Tepe, and
Sange Chaxmaq. The nearby
Shahroud Plain has many such sites. More than 50 are on the
Gorgan Plain. According to the Greek historian
Arrian,
Zadracarta was the largest city of
Hyrcania and the site of the "royal palace". The term means "the yellow city", and it was given to it from the great number of oranges, lemons, and other fruit trees which grew in the outskirts of that city. Hyrcania became part of the
Achaemenid Empire during the reign of
Cyrus the Great (559–530 BC), its founder, or his successor
Cambyses (530-522 BC). The
Great Wall of Gorgan, the second biggest defensive wall in the world, was built in the
Parthian and
Sasanian periods. At the time of the
Sasanians, "Gurgan" appeared as the name of a city, province capital, and province. Gorgan maintained its independence as a
Zoroastrian state even after
Persia was conquered by the Muslim Arabs in the 7th century. In 1210, the city was invaded and sacked by the army of
Kingdom of Georgia under command of the brothers
Mkhargrdzeli. "Old Gorgan" was destroyed during the
Mongol invasion in the 13th century, and the center of the region was moved to what was called "Astarabad", which is currently called "Gorgan". Gorgan with its surrounding regions was sometimes considered part of the
Tabaristan region. Astarabad was an important political and religious city during the
Qajar era. ==Demographics==