Welcome to LagosThree part observational documentary series which explores life at the sharp end of one of the most extreme urban environments in the world: Lagos, Nigeria.

Fifty years ago, Lagos, then Nigeria's capital, was a city the size of today's Bradford, with a population of a little less than 300,000 people. Everyone said it was lovely. Now 16 million people live there: it is one of a new breed of megacities in a world that is abandoning the countryside. And it grows by 600,000 a year.

That's like chucking in Glasgow every 12 months. It's a monster, force-fed to morbid obesity, but with the bone structure of a baby. It can't function properly, just lies there growing, groaning, and threatening to burst. No one says Lagos is lovely any more.

It is extraordinary, though, as is this documentary, Welcome to Lagos (BBC2), which zooms in on a handful of those 16 million. Bottom of the pile, literally, are the scavengers at the Olusosun rubbish dump, human vultures who pick through the stinking detritus with metal claws, looking for stuff that can be recycled and sold: tins, plastic, copper wire, rubber, clothes, anything.

In the dry season, fires often break out, adding toxic smoke and mortal danger to a day's work. And in the rainy season, the place turns into a slimy netherworld.

Watch the full documentary now (playlist - 2 hours, 48 minutes)