After the Islamic conquest of Persia, Zoroastrian fire temples, with their four axial arch openings, were usually turned into mosques simply by setting a mihrab (prayer niche) on the place of the arch nearest to qibla (the direction of Mecca). This practice is described by numerous Muslim sources; however, the archaeological evidence confirming it is still scarce. Zoroastrian temples converted into mosques in such a manner could be found in Bukhara, as well as in and near Istakhr and other Iranian cities,[1] such as: Tarikhaneh Temple, Jameh Mosque of Qazvin, Heidarieh Mosque of Qazvin, Jameh Mosque of Isfahan, Jameh Mosque of Kashan, Jameh Mosque of Ardestan, Jameh Mosque of Yazd, Jameh Mosque of Borujerd, Great Mosque of Herat as well as Bibi Shahr Banu Shrine near Tehran.