Megacities

Click here to watch Andrew Marr's Megacities (about Dhaka, London, Shanghai and Mexico City).

Below, you can find some more documentaries on some megacities:

Dhaka (the fastes growing megacity in the world)

Mexico City

Sao Paulo

Here's the fill in exercise about Mexico City.

And, last but not least, here are a whole bunch of listening, reading and grammar exercises on megacities which will certainly contain something that is useful to you. 

Enjoy!