ANCIENT megaliths like Britain's famous Stonehenge monument were actually invented by the French.

That's according to a new study, which says the French used the huge stone structures as graves before the idea spread to other parts of Europe, including the UK.

Building practices spread as far as Sweden as ancient people sailed around the continent, researchers said.

Around 35,000 megaliths – ancient monuments built from large stones – have been found throughout Europe.

Many were built during the Neolithic and Copper ages and are concentrated in coastal areas.

Scientists at the University of Gothenburg in Sweden analysed more than 2,000 radiocarbon dates of ancient stone structures.

The earliest megalithic graves emerged in northwest France during a period of 200-300 years in the second half of the 5th millennium BC, they found.

But they also popped up in the Mediterranean and the Atlantic coast of the Iberian Peninsula at around the same time.

However, monuments constructed before this period were all built in northwest France.

Thousands of megalithic graves were erected in France, the British Isles, and the Iberian Peninsula during the first half of the 4th millennium BC.

Many more were constructed in Scandinavia during the second half of the millennium.

The distribution of the graves suggests the concept was born in northwest France, but was later spread to other parts of Europe via sea trade routes.

Much mystery still surrounds the megaliths of Europe.