View over the shantytown of West Point, Monrovia, Liberia, West Africa, Africa

Hillside shantytown (favela), Rio de Janeiro, Brazil, South America

Morro da Providencia favela overlooking Guanabara Bay in Rio de Janeiro, Brazil, South America

Historic building evoking the west coast's gold-mining past, Shantytown, Greymouth, Grey district, West Coast, South Island, New Zealand, Pacific

Historic building evoking the west coast's gold-mining past, Shantytown, Greymouth, Grey district, West Coast, South Island, New Zealand, Pacific

Thailand mother breast feeding baby. Inhabitants of a slum in chiang mai

Thailand mother & baby, chiang dao village, near chiang mai

Thailand mother & child, slum dwellers of chiang mai

Honduras slum dwellers of tegucigalpa

Namibia billboard warning against domestic violence. Slum district of katatura, windhoek

Thailand slum dweller pumping water, chiang mai

Kenya makuru kayaaba a of nairobi

Philippines child living in a shantytown dwelling near garbage tip at bagong silangan, quezon city, manila

Philippines boy wearing a headlamp. He is getting ready to scavenge on the dump. Shantytown dwelling near garbage tip at bagong silangan, quezon city, manila

Honduras neighbours visiting in a slum of tegucigalpa

Kenya. Woman collecting water from public tap in mukuru ruben, a slum of nairobi

Brazil the favela of peixhinos, recife

Cinder block homes cover the mountainside in Petare, Latin America's largest shanty town, in Caracas, Venezuela, July 23, 2008.