Christine Bleakley takes to a helicopter to view remains that are best seen from the air, while historian Michael Scott is on the ground to explore further what each sky-high vantage point reveals. Their journey takes them from London, across to Wales and north to Hadrian's Wall, visiting fascinating sites that include the best-preserved Roman legionary barracks anywhere in Europe, the 6,000-seat amphitheatre at Caerleon and town walls that stretch for more than a mile