Al-Masjid an-Nabawi is a mosque established and originally built by the Prophet Muhammad, situated in the city of Madinah in Saudi Arabia. Al-Masjid an-Nabawi was the second 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 Makkah. It is always open, regardless of date or time.