The second holiest site in Islam is Medina (or Medinah), the "City of the Prophet," is in the Hejaz region of western Saudi Arabia. It was to Medina city that Muhammad fled when he was initially driven out of Mecca, and the place where he attracted his first followers. Medina currently has a population of about 600,000 people and is the home of "The Prophet's Mosque."
The long form of the Arabic name for Medina (Madinat Rasul Allah) means "City of the Prophet of Allah", while the short form (al-Madina) just means "the City". Muslims always add salla Allahu alayhi wa sallam ("peace be upon him") after mentioning the Prophet Muhammad, so the full form of the name is commonly given as "Madinat Rasul Allah salla Allahu alayhi wa sallam."
Medina is the second holy city of Islam, after Mecca. Its importance as a religious site derives from the presence there of the Masjid al Nabawi, the Mosque of the Prophet, which was built on the site of Muhammad's home and is where he is buried. The first mosque of Islam is also located in Medinah and is known as Masjid al-Quba, the Quba Mosque.