Pssst. Wanna see some good maps? Try this on for size:

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That is the population density of the Greater London area, represented by both colour and bar height: flat, blue areas are the countryside; tall, dark red ones are basically Hong Kong on Thames. The tallest bar, poking so far out of the East End that from this angle it seems to reach into Hertfordshire, is Canary Wharf, where a lot of people live in a very small space.

All this the work of Leeds-based mapping and data visualisation studio Parallel. (The science part: it’s mid-2015 population estimates for the lower super output areas used by the Office for National Statistics.) The map on their site is fully interactive. So you can rotate it, to look down from above:

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…which mostly goes to show how under populated the London borough of Bromley is compared to all the others.

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If you keep zooming out – which, admittedly, involves changing your browser settings (Ctrl + -) ­– you can start to see the shape of the capital’s commuter belt. It seems to extend further from west to east, along the Thames from Reading to Southend, than it does from north to south, where hills start to get in the way.

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Up in the Midlands, you can see how Birmingham and Wolverhampton are a single conurbation, but Coventry is separated from it by several miles of open countryside – just one of many smaller cities with close ties to Birmingham.

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It’s a similar effect in the north east where green belt means Sunderland still stands slightly apart from the rest of Tyne & Wear.

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Looked at like this, Liverpool and the Wirral look like one city, but the towns of the borough of Sefton (Southport, Formby) look separate.

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Greater Manchester looks more coherent, although Wigan, far to the west, doesn’t look much more integrated than Warrington.

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Zoom out, and you can sort of see how Manchester sits at the centre of a network of northern towns and cities.

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Even if you zoom further out, sort of. I’ve circled Manchester in yellow, to highlight the point:

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We’ve not really talked about Wales. Mostly because it’s basically empty.

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You can even spin the map round, if that’s your bag.

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Wheeeeeeeeeeee!

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I’m going to stop there because I could keep going all day. Anyway – you should go play with the map yourself, is the point. Here’s the link.

Jonn Elledge is the editor of CityMetric. He is on Twitter, far too much, as @jonnelledge.

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