African voodoo followers celebrate in Ouidah, Benin, on the final day of the country's ten-day Voodoo Festival. Devotees broke bottles on their heads and offered their blood to the gods as part of the ritual event.
Though often associated with zombies and "voodoo dolls," voodoo is actually a West African worship system that focuses on the veneration of ancestors and the deities they served. The religion has spread to many other locations, such as the Caribbean country of Haiti.