Great Mosque Cahar Derakht of Birjand.

Late Qajar mosque, located in Birjand, in the district of Cahar Derakht, of the four trees, is one of the main places of worship in the region. it was built as a nave and the particular architectural structure constitutes a great interest for scholars and enthusiasts.

Inside the mosque there are two altars, according to tradition one for the Sunni faithful and one for the Shiites, to celebrate the union between the two cults. However, according to another tradition, an altar was built facing Jerusalem, out of respect for the first qibla of Muslims, and one facing the Kaaba.