The last of the Five Pillars of Islam is the Hajj, or pilgrimage to Makkah (Mecca).
Muslims are encouraged to make at least one trip to Makkah during their life. This is usually done during the annual Hajj in the twelvth month of the lunar calender.
During the Hajj, several rites are performed such as circling the Ka'ba seven times and passing between the mountains of Safa and Marwa as Hagar did. During last rite of the pilgrimage all of the pilgrims stand together on the plain of Arafa and pray for god's forgiveness.
Around two million pilgrims travel to Makkah each year.