The annual pilgrimage to Makkah - the Hajj - is an obligation only for those who are physically and financially able to perform it. Nevertheless, about two million people go to Makkah each year from every corner of the globe providing a unique opportunity for those of different nations to meet one another. Although Makkah is always filled with visitors, the annual Hajj begins in the twelfth month of the Islamic year (which is lunar, not solar, so that Hajj and Ramadan fall sometimes in summer, sometimes in winter). Pilgrims wear special clothes: simple garments which strip away distinctions of class and culture, so that all stand equal before God.