Medina (often spelled Madinah) is known as the 'city of the Prophet'. It is where Islam's founder, Muhammad, was given refuge after being exiled from Mecca. Here he lived, built his mosque, fought pivotal battles, and it's where he was finally laid to rest. Monuments to this seminal period of his life are what pilgrims from all over the world come to visit, but the city's central area is off limits to non-Muslims.
The significance of the Prophet's time here is acknowledged by the fact that the Islamic calendar starts from 622, the year he arrived in Medina.
The modern city, like Mecca, is centred around a grand mosque, the Prophet's Mosque, which has a series of large numbered gates often used to navigate the pedestrianised area in and around it. Its surrounded by high-end hotels and eating outlets, with the rest of Medina sprawling out from here.