Kenya's huge and squalid slums don't have much of anything, except mountains of trash that fill rivers and muddy streets, breeding disease. Now Kenyan designers have built a cooker that uses the trash as fuel to feed the poor, provide hot water and destroy toxic waste, as well as curbing the destruction of woodlands. After nine years of development, the prototype “Community Cooker” is close to being rolled out in overcrowded refugee camps as well as slums around the country where the filth encourages diseases including cholera. Invented by Nairobi architect Jim Archer, the cooker combines simplicity with the capacity to confront several environmental challenges simultaneously. The design was highly commended at the World Architecture Festival in Barcelona last year. The prototype is working in Nairobi's Kibera slum, said to be the biggest in Africa, where around 800,000 people live. Potatoes, rice and tea cook on some of the eight hotplates above a roaring, spitting furnace. A joint of meat roasts in an oven that can also be used for bread. Behind the black-painted corrugated iron cooking area, rubbish collected by local youths dries on racks before being pushed into the furnace. Technicians have spent three years modifying the firebox to produce enough heat to destroy toxins in the rubbish, particularly plastics, although they are striving to get the temperature higher still. The stove is one of several projects giving hope amid endemic violence, crime and disease in the huge slums. In another part of Kibera, a group of 35 youths have developed a farm on a former rubbish dump, feeding themselves and selling cucumbers, pumpkins and tomatoes.