Europe's stone megaliths: How did they get here?

Across Europe, some 35,000 stone megaliths continue to fascinate tourists and archaeologists alike. The simplest consist of a single large stone - and the most complex include architectural marvels like Stonehenge in England. For years, it was thought that different communities came up with the practice independently of each other. But new carbon-dating research suggests they actually originated in France. We speak to prehistoric archaeologist Dr Bettina Schulz Paulsson about her findings.