In Mamatin region, at a distance of 25 km from east north of Ramehr Maz, there are many springs which tar is coming up of them naturally. These 10 tar springs are like bakery oven.
They are made of stone and mortar. These springs are located on both sides of a water-less ravine. A black gold, which is combined with oil, is boiling from springs also it is combined with Zard Ramehr Maz river's water so its thick will decrease.
When these springs bubble, they will locate at riverbed, so this can be the reason for emergence of a very beautiful rainbow on river.