Hajj is the fifth of the five pillars of the Islamic religion that all Muslims who are financially and physically capable must perform at least once in their lifetime. It is the annual pilgrimage to Mecca, Saudi Arabia that has to be performed during Dhu al-Hijjah, the last month of the Islamic calendar. The pilgrimage is one of the largest gatherings of Muslims in the world. There are two Hajj pilgrimage types, Umrah and Hajj. Umrah is a Saudi Arabian pilgrimage to Mecca. It is a religious obligation that every Muslim is expected to complete at least once in their lifetime. It can be done at any time of the year. There are thousands of people from all over the world who go on Hajj every year.