A woman collapses in a trance after being possesed by the voodoo spirits in Ouidah, Benin.

Watch: Voodoo Festival celebrated in Benin

Every year in Benin, west Africa, locals celebrate a festival in tribute to the deities of Voodoo, the indigenous religion worshipping natural spirits and revering their ancestors.

Every year in Benin, west Africa, locals celebrate a festival in tribute to the deities of Voodoo, the indigenous religion worshipping natural spirits and revering their ancestors.

Increasingly, the festival draws people of African descent from America, Brazil and the Caribbean seeking to discover the religion and land of their enslaved ancestors.

Voodoo, known locally as Vodoun, originated in the Dahomey kingdom, present-day Benin and Togo, and is still widely practised sometimes alongside Christianity in coastal towns like Ouidah, once a trading hub where memorials to the slave trade are dotted around the small beach settlement.