The Stars Valley, which in the local dialect is called Staleh Kafteh, is one of the rarest erosion phenomena in Iran. This valley generally has several branches linked to each other and contains a series of various geological phenomena. The effect of flowing water erosion caused by rainfall has had the maximum impact on forming this valley and its terrains. The other factors like the difference in material and strength of different layers, the presence of intercalated bed and streaks of gypsum, as well as internal movements and pressures of the earth (tectonics) contributed to the formation of this valley. The walls are made of two different substances with varying hardness and resistance: a thick but soft layer of cream to the light gray below and a thin but hard and fragile layer on top. The soft bottom layer is rapidly worn away by the erosion factors, but the top layer is resistant to wearing down due to its natural calcareous cement and protects the bottom layer like a shield. Wherever the top layer is removed or has cracks and crevices, erosion occurs more rapidly and intensely, causing small valleys and various fractures to appear. The floors and layers of this valley, because of the mentioned features, are exceedingly sensitive and vulnerable. Even the weight of a man on its floors can be excessively dangerous and cause sudden collapse while the place may appear solid and integrated, but the layers below are removed and hollow. Stepping on these floors, even if not cause to fall at the moment, will reduce the strength of the hard uppermost layer and create very small cracks and fractures in its structure, and eventually lead to its rapid destruction. Therefore, banning stepping on the outer layers of the valley will help preserve this unique and valuable natural monument, considered a geological heritage. The Aghajari Formation is the main formation of the Stars Valley. In the sedimentary sequences of the Aghajari Formation, fossils of living organisms like oysters, gastropods, echinoderms, and various corals are found in abundance. The accumulation of fossils in some parts of the sequence is recognized as a layer of Lomashell. The age of constituents in the Stars Valley is Middle (Tortonian) to Late (Messinian) Miocene (between 5 and 10 million years), while the formation of the valley and its terrains date back to the last tens of thousands of years. According to local beliefs in the past, this valley was created by the stroke of a star (meteorite), which caused to rising of rock and soil and the solidification of these materials in the air, so people attribute the columnar and needle-shaped figures to this event. For this reason, the local name of Estareh Kafteh, which means the fallen star is referred to it. In the past, it was also believed that in the sunset, this valley is haunted by jinns and ghosts, and the sound of the wind blowing in the valley was attributed to this issue.