Mysterious Train

 I found this picture on the National Geographic Traveller UK's Facebook page, a few weeks ago. But from what I read the picture might have been taken in Germany. I don't care one bit about the walking couple one bit. What caught my attention is the steam train in the background. Wherever it is, I want to go there. So I am going to plan our next UK holiday trying to solve this mystery: where is that train? And if it is in Germany, well... I will try to convince my wife to go there.