How much space would the Pentagon take up if, for some absurd reason, it had been built in Trafalgar Square? How about the Giza pyramids? Or Stonehenge? Or even a deep sea trawler net? And did you know that the deepest hole ever drilled, if somehow laid out horizontally, would stretch from Tooting to Hampstead? Mind that gap.
These and many other lunchtime-killing visualisations are available over at BBC Dimensions - a terrific new site that helps us appreciate the scale of famous objects by placing them over familiar terrain. It's not an original idea, by any means, but by building an intuitive platform that can be expanded (and hopefully opened up to user data), it's certainly a big advance.
You can centre the objects at any postcode. Unfortunately, you can't grab and embed the resulting maps, which means we can only show you a static image here. The concept, whose genesis you can read about here, was developed by design consultancy Berg. We wonder how big the crowd of applauding users would look if plotted over central London?