Gorgan formerly Astarabad is the capital city of Golestan Province, Iran. It lies approximately 400 kmto the north east of Tehran, some 30 km away from the Caspian Sea.
There are several archaeological sites near Gorgan, including Tureng Tepe and Shah Tepe, in which there are remains dating from the Neolithic and Chalcolithic eras. Some other important Neolithic sites in the area are Yarim Tepe, and Sange Chaxmaq. The number of confirmed Neolithic sites on the Gorgan Plain now totals more than fifty.
The Great Wall of Gorgan, the second biggest defensive wall in the world, was built in the Parthian and Sassanian periods.
At the time of the Sassanids, “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 8th century.

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The Great Wall of Gorgan is a Sasanian-era defense system located near modern Gorgan in the
It is 195 km long and 6–10 m wide, and features over 30 fortresses spaced at intervals of between 10 and 50 km. It is surpassed only by the walls systems of Great Wall of China as the longest single-segment building and the longest defensive wall in existence.
The wall is located at a geographic narrowing between the Caspian Sea and the mountains of northeastern Iran. It is one of several Caspian Gates at the eastern part of a region known in antiquity as Hyrcania, on the nomadic route from the northern steppes to the Iranian heartland. The wall is believed to have protected the Sassanian Empire to the south from the peoples to the north, probably the White Huns. However, in his book Empires and Walls, Chaichian (2014) questions the validity of this interpretation using historical evidence of potential political-military threats in the region as well as the economic geography of Gorgan Wall’s environs. It is described as “amongst the most ambitious and sophisticated frontier walls” ever built in the world, and the most important of the Sassanian defense fortifications.

Khalid Nabi Cemetery is a cemetery in northeastern Iran’s Golestan province near the border with Turkmenistan, roughly 60 kilometers northeast of Gonbad-e Kavous city. It is mainly situated on a mountain ridge about 1 km distance from the mausoleum called “Khaled Nabi” who according to oral tradition was a pre-Islamic prophet.
The cemetery was visited in 1979 and 1980 by the archeologist David Stronach. He found over 600 standing stones which are spread out in several locations.
Stronach noted two types of gravestones on the site. In both he saw “highly stylized representations of people.”
Type 1 being of a cylindrical column type with a cap-like top with heights between 60 cm to 4 m. Many of them have horizontal ribs on the shaft. Stronach interprets type 1 stones as depictions of men with their caps, helmets and in some case with clearly visible turbans, pointing to parallels in Turkic Ottoman grave-markers.
Type 2 stones are generally smaller, have rectangular sections and two opposed high-set lobes. Stronach interprets these as human shapes with arms in akimbo position.

Gonbad-e Qabus is a monument in Gonbad-e Qabus, Iran, and a UNESCO World Heritage Site since 2012. It marks the grave of Ziyarid ruler Qabus (r. 978–1012), and was built during his lifetime in 1006/7. It is a cylindrical tomb tower that reaches c. 61 metres (200 feet) and can be seen from some 30 kilometres away. The eponymous city is named after the monument.
Considered to be a masterpiece of Iranian architecture. it achieves an “almost perfect balance between a purpose (princely glory beyond death), a form (cylindrical tower transformed into a star), and a single material (brick). The Gonbad-e Qabus tower is the best known tower tomb in northern Iran .
The monument has an interior diameter of 9.67 metres at its base. the building’s entrance contains some of the earliest evidence of the development of the moqarnas structure.
Taking its conical roof into account, the tower measures c. 50 metres above ground.