The Mashhad Radd al-Shams (Arabic: مشهد رد الشمس, romanized: Mashhad Radd al-Shams, lit. 'Shrine of the Return of the Sun' is a mosque located in Hillah, Babil Province, Iraq. It marks the spot where, according to local tradition, the sun stopped for Ali ibn Abi Talib when his followers missed the obligatory Asr prayer.^[1][2][3][4]

Originally on the site of the present mosque, there was a Babylonian temple dedicated to worshipping the sun.^[5] It was converted into a mosque during the Buyid era, and the dome and minaret were built in the Seljuk period.^[5] The mosque was attributed to Ali ibn Abi Talib, and it became a place that was revered by Shi'ites.

In 2022, it was reported that the conical dome of the mosque was in danger of collapsing.^[5] Cracks had started appearing on the dome, and this threatened the stability of the dome.^[5] The factors were said to have been erosion, as well as a lack of maintenance.^[5]

The mosque is divided into two parts. The first section leads into an open courtyard with corridors. The second section of the building comprises the mosque itself.^[6] A small cemetery is located next to the entrance of the second section, and one of the tombs is located next to a staircase which allows one to access the roof of the mosque.^[7]

The dome of the mosque is a conical shape, similar to the domes found in the Mausoleum of Umar Suhrawardi and the Zumurrud Khatun Mosque. It is 22 metres in height. This dome was built during the Seljuk period, over the original Buyid-era mosque. The mosque also has a single minaret, also a Seljuk construction.^[8] It is 15 metres tall, and topped by a blue dome. The minaret does not contain a staircase for the muezzin, the balcony is only for display purposes.^[9]

The mosque used to have a golden dome. It was even described by Al-Sayyid Kamal al-Din in his book "Fuqaha al-Fayha" and it was said to be famous for this feature. But this dome does not exist in present day.^[10]

• List of mosques in Iraq