Where do aeroplanes go to die? What happens to them after they're done with flying? In an unassuming corner of Wales lies one of the world's busiest yards for aircraft end-of-life services - home to dozens of these retired relics of the sky. With exclusive access to the day-to-day running of this bustling base, our cameras are on the scene as the team dismantle and breathe new life into these mammoth machines. Along the way, we examine their ground-breaking engineering, and undercover the stories and secrets they store with them.