With impressive architecture, food and drink outlets that rival city-center hotspots, and relaxation spaces fit for luxury hotels, these are the flight hubs worth lingering at Sign up to Simon Calder’s free travel email for expert advice and money-saving discounts Get Simon Calder’s Travel email Get Simon Calder’s Travel email Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice Most airports are soul-destroying places. But