spain's largest sand dunes, standing at over 30m high and 200m wide, all concealed within the estrecho nature parkably the best way to think about this coastline, which is endlessly shifting down the centuries, is as a living sand dune. and now, with climate change, the winds are getting stronger and pushing with them these dunes. so they're really moving? yeah, exactly. these dunes are being battered by hurricane force winds, forcing them inland and revealing some remarkable hidden history concealed below. if you think about it in terms of history, this is a melting pot of cultures. you've got africa, you've got europe, you've got all of the mediterranean, and then the travels across the atlantic. and all of those peoples have left their vestiges, their archaeological sites, along this coastline, which have been kept perfectly intact down the millennia. my next stop is cape trafalgar, 60km down the coast from bolonia, where archaeologists from the university of cadiz have just discovered some remarkable ruins, thanks to these moving sands. so when you discovered and realised it was a tomb, you mu