If you were asked to make a TV documentary, what would it be about?

Just say you were invited to make a TV documentary and it could be about any topic that you liked, what would you choose?

For me I admit I would end up making one connected to my archaeology and the Romans in Scotland, but I would look at certain sites and explain how we know different things about them rather than just saying that they were at a certain part of the country between certain years. I would also make sure that it was fun and interesting for children in the hope that they would learn from it and would then like to go on and learn more in their spare time.

So what would you make?