Al-Masjid an-Nabawī (; Prophet's Mosque) is a mosque established and originally built by the Prophet of Islam Muhammad. It is in the city of Medina in Saudi Arabia. Al-Masjid an-Nabawi was the third mosque built in the history of Islam and is now one of the largest mosques in the world. It is the second-holiest site in Islam, after Masjid al-Haram in Mecca.