Mihrab (a niche in the mosque wall marking the direction of Qiblah)
The word Mihrab in dictionaries means the noblest place for sitting and the noblest place in the mosque. In Islamic architecture, Mihrab is the recession in the middle of Shabestan (hall) wall, which is located in the direction of Mecca showing Qiblah. The congregational prayer Imam stands there and the worshippers say prayers following his lead in his back in the direction of Qiblah.
In fact, Mihrab is the heart of a mosque, and in terms of shape, it resembles a lamp that sheds light upon the place of worship and illuminates the direction of Ka’bah and God in the darkness of ignorance and oblivion. Mihrab is the most spiritual and ornamented part of a mosque, and the most glamorous and magnificent art works have been applied to this small space. Various kinds of plaster carving, tile work, different kinds of ornamental lines and vegetarian patterns and Quranic inscriptions have appeared in it. Furthermore, Mihrab is a place for the glittering of divine light, and is a gate opening to paradise.
This sense or concept is noticeable from the arch shape of Mihrab and the verses of Surah Noor that have surrounded it.

Mihrab is made like a sign and symbol marking the direction of Qiblah, and it is the place where congregational prayer Imam stands. It is made as a kind of empty space in the angle of the building, laying a wise emphasis on the immateriality and spirituality of Islam.
Nowadays, the first part of the mosque building to be decorated is Mihrab and the next one is the entry threshold, which is due to sacredness of the mosque building in comparison with the surrounding buildings. Mihrab is also decorated to suggest the spiritual relationship between Qiblah and divine presence and orients religious deeds in a universal radium, attracting the attention of all the believers to a single unified center