In Onsrood stair village near Oskoo city, you can find a rocky mosque which is constructed in heart of the mountain!
Its space is about 570 SM and is the largest rocky mosque of Iran. Its history backs to Qajar era of Iran while we can find some documents which demonstrate that its history perhaps backs to Ilkhani era. Some of researchers and specialists believe that its archaism could backs to more than 1500 years back!
A great and ancient treasure for Iran among her western beautiful and elevated mountains! 
