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The longest circuit in the world! Also known as the Green Hell. Located in the Eifel region in Germany between Trier and Koblenz. You can see it in the map here.

This race track is 20 kilometers long, 22 if you count the Formula 1 race track. Both are combined for special events such as the 24 hours of the Nurburgring.

The race track is currently used by car manufacturers and enthusiasts to test their wheels and balls of steel.

Here's an older preview but so well described

But it could actually look more like this...