Medina is home to the three oldest mosques in Islam, namely; Al-Masjid al-Nabawi (The Prophet's Mosque), Quba Mosque (the first mosque in Islam's history), and Masjid al-Qiblatain (the mosque where the qibla was switched to Mecca).
Because of the Saudi government's religious policy and concern that historic sites could become the focus for idolatry, much of Medina's Islamic physical heritage has been destroyed since the beginning of Saudi rule.
The Islamic calendar is based on the emigration of Muhammad and his followers to the city of Medina, which marks the start of the Hijri year in 622 CE, called Hijra (هجرة).
Similarly to Mecca, entrance to Medina is restricted to Muslims only; non-Muslims are neither permitted to enter nor travel through the city. Muslims believe that the latter verses of the Quran were revealed in Medina and its surrounding outskirts, called the medinan suras.