Mohammad Hossein Azizi Kharanaghi - Assistant Professor of the Iranian Center for Archaeology (ICAR) .
Masashi Abe - Tokyo National Research Institute for Cultural Properties
Sepideh Jamshid Yeganeh - Graduate of Master of Archeology, University of Tehran. Tehran. Iran.
Afshin Akbari - Graduated from the Department of Archaeology, University of Tehran. Tehran. Iran.

Eastern Iran, especially in the prehistoric period, is a completely unknown region on the Iranian archaeological map. More than one hundred years after the beginning of archaeological excavations in Iran, the eastern regions have received little or no attention from archaeologists for various reasons, and there are very limited publications as well. Kale Kub is a prehistoric site that is located in Ayask town, in Sarayan District, South Khorasan Province, eastern Iran. It has sufficient cultural deposits to provide a chronological timeframe of cultural sequence for the prehistoric cultures of this region. The first season of Kale Kub excavations, carried out in ۲۰۱۹, led to the identification of unknown prehistoric cultures in the region, which are introduced in this article.         Perhaps the most significant achievement of this excavation was the identification of the ۴th millennium BCE cultures, which are well known in the southwest of Iran and Mesopotamia and for which evidence has been obtained far from the centre of this culture. These cultural evidences, which can be considered to belong to the Susa II horizon or late Uruk cultures, include the typical pottery of this period, such as bevelled rim bowls, rough Banesh trays, tubular and nose handle jars, and fine and painted wheel-made pottery, which is well known in the south-western, western, north-western, south-eastern regions and central plateau of Iran, but which have now been identified and introduced for the first time in eastern Iran. In general, based on the excavation of two stratigraphic trenches (A and B) in this site, three cultural periods have been identified so far. They have been classified from the bottom level and the top of the virgin soil are: ۱: KALE KUB I (Chalcolithic period, fifth millennium BCE), ۲: KALE KUB II (Susa II horizon, fourth millennium BCE), and ۳: KALE KUB III (Bronze age, third and second millennia BCE).