Gonbad-e Kavus () is a city in Golestan province, Iran. The modern name, meaning "the tower of Kavus", is a reference to the most imposing ancient monument in the city. The historic name cannot now be restored, because it was assigned to the neighboring historical city of Astarabad in the 1930s by the Iranian government. At one point, it was even known as the city of Dashte Gorgan, meaning "the Plains of Gorgan". It is the capital of Gonbad-e Kavus County, in the province of Golestān in the northeast of Iran. At the 2006 census, its population was 127,167, in 30,710 families. In the historical times, the city's populations were made up of various Iranic peoples such as the ancient and eponymous Hyrcanians, Parthians and eventually the Khurasani Persians. Today, however, there are no reliable figures for the ethnic make of the city. However, it is agreed that the city has a plurality of its inhabitants being a mix of ethnic Persians, Turkmen, Turkmen remaining population are made Azerbaijanians, Sistani Persians, Baluch and other Iranic peoples. The city is famous for its historic brick tower of the same name. The city has an ethnically diverse population and the biggest ethnic group is Persians followed by Azeris and Turkmens. The Persians and Azeris tend to mainly follow Shia Islam while the Turkmens are mostly Sunni Muslim. Historical attractions The "Divar-i Gorgan" (Persian for "The Great Wall of Gorgan") is a gigantic defensive wall built in the Sasanian period of Iranian history. The visible remains are about long and wide. It is one of the most outstanding and gigantic architectural monuments in northeast Iran and the most impressive in the Golestan Province. This wall, which is the largest defensive wall in the world after the Great Wall of China, starts from the Caspian sea coast, circles north of the city of Gonbad-e Kāvus, continues towards the northeast, and vanishes into the Pishkamar Mountains. At certain points, the Divar is wide and in other parts the width is , depending on the nature of the land and the soil type. Watch towers and forts had been built at different distances. The longest distance between forts is and the shortest is . The 40 identified forts vary in dimension and shape but the majority are square fortresses. Due to many difficulties in development and agricultural projects, archaeologists have been assigned to mark the boundary