Al Masjid Al Nabawi
A huge mosque in the city of Madina, and built by the Prophet Mohammed, it is also where he and his close companions are buried. Each of the pillars, domes, and windows in the mosque tells a story and indicates the location of events of historical and spiritual significance. It is the second holiest site in Islam, after the Kaa'ba (which is housed in the Great Mosque) and is the third mosque to ever be built in Islam. It has been rebuilt and extended over hundreds of years so that is now one of the largest mosques in the world.