Exploring Britain's coastline. Coast ventures to brand new territory, the storm battered Atlantic shore of Ireland's majestic northwest coast. Local legend says that Clew Bay has 365 islands, one for each day of the year; Nick Crane investigates how this astonishingly beautiful and unusual landscape was created when Ireland was covered in ice. Neil Oliver discovers how the infamous 16th century Pirate Queen Grace O'Malley turned her coastal home into an impregnable fortress. And Alice Roberts unearths the remarkable remains of the oldest farm in the British Isles, a complex system of walls and houses laid out before Stonehenge; the ancient ruins of these Stone Age farmers have been buried in the peat for over 5000 years.