The Pilgrimage is one of the most popular and collective human activities, and continues to grow in size. Tens of millions of Hindus bathe in holy waters at the Kumbh Mela. Jews from around the world make their way to the Western Wall in Jerusalem. Islam has the Hajj and Christians have walked the same paths for centuries. Others find themselves on a pilgrimage for very different reasons. Mike Williams finds out why.

(Photo: The Grand mosque and the Kaaba in the holy city of Mecca. Pilgrims pelt pillars symbolising the devil with pebbles to show their defiance on the third day of the hajj to mark Eid al-Adha or the Feast of the Sacrifice. Credit: Fayes Nureldine/AFP/Getty Images)