Can you tell what this is?

I’ll give you a hint.

It’s in a London museum.

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Another clue?

I’m guessing it’s about 50 feet across.

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The hole is large enough for people to fit through standing up.

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Ok. I’ve kept you in suspense long enough.

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It’s the entrance to an exhibit about the history of the Earth in the Natural History Museum in London. There is an escalator that goes up through a giant globe. This is a long exposure so the people are blurred.

Here’s another picture so you can see it better.