Both Sunni Muslims and Shia Muslims agree on the three holiest sites in Islam being, respectively, the Masjid al-Haram, in Mecca; the Al-Masjid an-Nabawi, in Medina; and the Al-Masjid al-Aqsa, in Jerusalem.

The Al-Sahlah Mosque is one of the primary significant mosques in the city of Kufa, Iraq. The mosque is of great importance to Shia Muslims, and it is believed that the mosque was initially established in Kufa as a neighborhood mosque for the followers of Ali, the early members of the Shia. The mosque is also said to be the future home of the Twelfth Shia Imam, Hujjat-Allah al-Mahdi.