(CNN) Five measly feet.

That's the distance that caused Fan y Big, a peak in the Brecon Beacons National Park in south Wales, to lose its status as a mountain. Now it's merely a hill.

What happened? Did this mound shrink?

Not really. Fan y Big is still tall enough. But improved technology complicated things.

This popular hiking spot has long enjoyed a place on the list of Hewitts -- also known as mountains -- in England, Wales and Ireland.

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