And by day:
Now, some facts.
The tower weighs around 10,000 tonnes.
There are just over 18,000 metallic parts in the tower, held together by 2.5 million rivets.
It's painted with 60 tons of paint every few years to stop it rusting.
It sways a couple of inches in the wind.
It's the most-visited paid monument on Earth.
Alan White is a news editor for BuzzFeed News and is based in London.
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