Left behind from ancient civilization of Parthian dynasty, Niasar Cave in Kashan is a man-made cave that functioned as a Mithraist Temple just like other Mithraist temples. Just like the Niasar cave, most Mitra temples have been built in full darkness. Altogether, the cave consists of twenty rooms including large to small chambers, as well as grindstones to cover the passages in case of strangers’ outbreak, corridors, tunnels, a main entrance and three other entrance near the cliff of Niasar waterfall. Moreover, the chambers and floors were made in such way that the air circulates perfectly even in lowest stories. The objects found in the cave such as coins, millstones and potteries prove the fact that the cave were used in different periods of time. Many tales are being narrated by locals about this cave, but the most well-known is about a stonecutter who was spellbound. Some believe that the sound of his ax, carving the stones, can still be heard. To walk through most corridors, passages and even in small chambers, visitors have to creep and crawl.