The Hajj is an annual Islamic pilgrimage to Mecca, Saudi Arabia, which is the destination for the Hajj. Mecca is a city in the Hejaz region of Saudi Arabia and is the holiest city in Islam. It is the birthplace of the Prophet Muhammad and the site of the Kaaba, the holiest site in Islam. The Hajj is one of the five pillars of Islam and is a mandatory religious duty for Muslims who are able to make the journey.