Last Night's TV: Greatest Cities of the World with Griff Rhys Jones, Channel 4<br />Welcome to Lagos, BBC

I didn't see the first series of Greatest Cities of the World. It was in 2008 and only three episodes long. Back then, Griff Rhys Jones went to New York, London and Paris, which I suppose are OK choices if you're only allowed three. Last night though, in the first of a new series, Rome got a look in. We were, said Rhys Jones, going to see a typical 24 hours in the life of the city and its people.

So, naturally, he hitched a ride with a farmer (the subway in Rome is rather limited, I understand, so this is what they do instead. Or something. At any rate, we'll hear about their transport problems later). Off Griff went, bouncing on the back of the fruit-and-veg truck – "it's the original city commute" – like an overexcited pumpkin (una pomodoro troppo eccitato). Rome being the capital of car crashes (don't pretend you're surprised), it wasn't long before we were chatting with a traffic cop. Naturally, the most important thing about policing in Italy is ensuring one masters the correct hand gestures. "They must be soft," Papa Policeman explained. "Sweet and fluid."

And so again to the problem of public transport. There might, of course, be fewer collisions were more Romans to take the underground. Unfortunately, there are only two lines. Ever since construction started, all the way back in 1955, they've had the same predicament: each time they start digging, they hit something of historical import. The whole network is one big archaeological site – a proper one too, not, as Griff neatly puts it, the British kind "where we find a few bits of pottery and Tony Robinson has an orgasm". It is amazing, really, when you think about it. Londoners are always banging on about how lucky they are to live in a city where you are "surrounded by history" – and we are, of course – but to live in Rome, where the kind of history you're talking about goes so far back that it's almost impossible to comprehend... Well, that must be astonishing. Or maybe you just get used to it. Probably. Mr Policeman didn't seem particularly awed.

Anyway, back to the point: a typical Roman day. Hitch a ride with a farmer, chat up a policemen, complain about the public transport... Sounds about right. Next? Ah yes, Un espresso. Coffee at a local coffee bar was a rushed affair (no lingering over the laptop, there, of course), swiftly followed by... a look at the sewage system. Hang on, Griff, I'm on to you. This isn't a typical day at all. No one in Rome hitchhikes into town before popping down to check out the sewage works and take mass with a bunch of nuns. It's a gimmick!

Still, as far as gimmicks go it's not bad. In this age of 20-pence flights to Istanbul (Icelandic volcanoes notwithstanding), it's all too easy to be blasé about somewhere like Rome. You know: "Oh, yes, yawn, went there for a weekend, coffee's nice have you been to Bangkok/Poland/Tazmania recently?" But of course, Rome is amazing. Europe's amazing. There's so much to see. Though, uh, I wouldn't start with the sewage works if I were you. (Also, is anyone else convinced that Griff is turning into Rob Brydon? I'm not being Welshist or anything. But look at him. Don't you just want to call him Uncle Bryn?)

And so, from one of the greatest cities in the world to one of the biggest: Lagos. I wonder if it, too, might be worth a visit from Griff. The pair aren't, after all, terribly different: both hives of activity, immensely confusing to an outsider, and I wouldn't mind betting that the traffic in Lagos is pretty bad too. Whether or not it's as inviting is another question entirely, of course, though the dynamism of its inhabitants and the vibrancy of its quarters must count for something. Last night, we got part two of Welcome to Lagos and it was just as determinedly cheerful as part one. Too cheerful, I think: Pollyannaish in the face of poverty.

That wasn't, though, enough to detract its merits. This time we were in Makoko, the city's waterborne slums (or "their very own version of Venice", depending on how you look at it.) Where Rome revolved around ruins, this city's life is governed by water. School buses float down water, businesses are built on water, and deaths are caused by water. Lots of deaths. We met Paul, a saw operator at the local timber plant, who can't save any money because he keeps spending it all on funerals. His colleagues, he explained, are constantly getting electrocuted.

More fortunate was Chubbey, who, with 18 children and five grandchildren to support, claimed to have worked out a formula to win the national lottery. He'd also worked out a scheme to make a substantial amount of money: erecting a pond outside his home (this being Makoko, where the houses exits on stilts, that simply means sticking up a fence around your front door) and breeding fish. When they began to mate, he started frying the offspring, selling them as street (river?) food. The business took off, and the cash rolled. Miraculously, he also managed to net a substantial win on the lottery, so maybe he had worked out the formula after all. "This is why people come to Lagos!" he laughed. "You pay a little, and you get a lot!"