The focal point for every Muslim and the biggest mosque in the world, Al Masjid Al Haram is able to host a million worshippers and covers an area of 356,800 sq metres. At its epicentre is the Holy Kaaba, covered in black and gold cloth, around which Muslims can be found circumnavigating night and day (known as tawaf). It's the holiest structure in all of Islam and is at the heart of the Islamic pilgrimages (hajj and umrah).