The Hajj is a pillar of Islam involving travel, which is a four-letter word in the crossword. The Hajj is an annual Islamic pilgrimage to Mecca, Saudi Arabia, and is one of the five pillars of Islam. It is a religious duty that must be carried out at least once in a lifetime by every able-bodied Muslim who can afford to do so. During the Hajj, pilgrims perform a series of rituals, including walking seven times around the Kaaba, the holiest site in Islam, and running between the hills of Safa and Marwah. The Hajj is a demonstration of the solidarity of the Muslim people, and their submission to God.