A stage production of E. Nesbit's children's novel The Railway Children recorded in the National Railway Museum in Yorkshire for TV broadcast. This recording is a bit obscure: TPL has a copy, but as I write the movie isn't listed in Wikipedia or on Rotten Tomatoes: I had to turn to IMDB. As one of the users there said, "This should not work but it does." The play has the three children (who I think are probably meant to be roughly 8, 10, and 12) played by young adults - who alternately refer to the history they're presenting to you ... and play the part of the children they were. It's well presented and surprisingly good.
A mother and three children move from London to Yorkshire when their father is imprisoned for an initially unspecified crime. They were well off, but now have to get by in much reduced circumstances. In the small town they now live in they often go to the railway station, where they make a variety of friends. The whole thing is sickly sweet in a way that only a British children's book from 1900 could be. It reminds me considerably of "Swallows and Amazons" in its excessive wholesomeness.
The play is staged with the audience sitting on bleachers on either side of a railway platform, and they make extensive use of three rolling stages to create rooms, simulate arriving/departing trains, or to indicate separation. Humour - particularly around the strange dual roles of the "children" as both children and adults - is used well and keeps the sickly sweetness from being overwhelming. A real lesson in how adapting for the stage can be done.