Glenfinnan Viaduct, ScotlandGlenfinnan Viaduct, deep in the Scottish Highlands. The Jacobite steam train crosses the concrete arches with a great plume of white steam trailing behind it, bright against the autumn hillside beyond. I'd say most people know this viaduct from the Harry Potter films, but it's been here since 1901, carrying the West Highland Line across the valley floor. What makes this work as a photograph is the light. Warm directional sun catches the right hand