The Great Mosque of Mecca is The Greatest Mosque on The World It is located in the heart of the city of Mecca in Tihamah, west of Saudi Arabia, That surrounds the Holy Kaaba Which is The First House of Worship That Was Established For The Mankind on The Face of The Earth To Worship The Only True God Allah, And It is The Greatest and Most Blessed Site on The Earth. And It is location determines the qiblah (direction of prayer). Wherever Ye are in the world, Ye are expected to face the Kaaba when Ye are performing Salah the Islamic prayer.