Mosque of Umer is one of the Seven Mosques located at the site of Battle of the Trench. It is located at the site of the command post of Umer ibn Khattab during the battle. Although the mosque is often visited by the pilgrims, there is no accounts in the order from the prophet Muhammad or in Sharia regarding the virtue of visiting these mosques.

The Mosque of Umer ibn Khattab at the site of Ghazwa-i Khandaq. Although pilgrims visit the mosque but there is no account of it's religious significance, it may just very well be of some historical significance. It is located 10 meters south of Abu Bakar As-Siddiq Mosque. This mosque is situated on higher altitude, and its look is corresponding to Al-Fath Mosque, thus it is considered that they were built and renovated at the same time.

The inner view of the mosque with the Mehrab in the background. The details of its origins are vague, al­though its name indicates that Khalifah Omar bin al-Khattab, the second caliph, may have had prayed there. The mosque features the same ar­chitectural characteristics as the Al-Fath mosque, indicating they were constructed during the same period. The mosques, in fact, are utilitarian and without adornment.

The older structure of Masjid-i Umar, it was recently renovated and a roof was installed over the open air courtyard. Electricity was provided and air coolers were installed. It represents a historical landmark, the site of the Battle of Trench, or Ghazwa-e-Khandaq, and is located on the western edge of Sela mountain.