Masjid al-Haram is the largest mosque in the world, capable of receiving over a million worshipers. It is located in Mecca and was built around the Kaaba, the holiest place for Muslims. Muslims believe that the Kaaba was originally built by Abraham with his son Ishmael, by God's order, and sent Abram into the world to invite believers to pilgrimage. It is not surprising, therefore, that Masjid al-Haram is the largest and holiest place of worship in Islam and the eighth largest building in the world. Only Muslims can enter the holy city of Mecca, so a visit to this magnificent building is reserved only for them.