The Nigerian city of Lagos, one of the world's fastest growing cities, has become a sprawling metropolis of high-rise buildings, new industry and heavy traffic with a population of 16m. The UN says numbers increase by almost 300,000 a year.
But behind the urban sprawl another type of business is taking place, in the most unusual of places. Around 1,000 people live and work on a rubbish dump which is situated right in the heart of the city.
The people living and working here see little difference between their trade and the trading taking place on stock exchanges around the world.
On the Olusosun dump, people live on top of the rubbish in houses built from scrap. They spend their days amongst the most potent of smells. Yet many here hope they can turn rubbish into gold.
Each day, 3,000 metric tonnes of rubbish are filtered by hand, keeping 500 people in full-time employment. They pick the most valuable discarded items to trade. Perfume containers, for example, are worth nine Nigerian naira (four UK pence; six US cents).
On the site itself there are shops, restaurants, bars, three cinemas, a mosque and even a barbers. Because of the facilities available, there are some people living in the dump who rarely leave.
Joseph is a trader who works to provide for his wife and two small children. He does not live on the dump but he has filled his house with things he has found there. It is even where he met his wife.
Eric, who both lives and works on the dump, juggles his life there with his aspiration to craft a career in music. No-one knows that Vocal Slender - as he is called - lives on the dump as he saves money for time in the studio.
Despite this optimism, there are many problems with living here. The natural gases that form under the decomposing waste, especially when it is dry, often lead to fires that are very difficult to extinguish.
But despite the difficulties and adversity they face, slum dwellers are adapting incredibly quickly to the realities of the world's increasingly extreme urban future, seeing opportunity where others just see junk.
The first of three episodes of the documentary Welcome to Lagos can be seen on Thursday 15 April 2010, BBC Two, 2100 BST and then afterwards on iPlayer in the UK.
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