A popular theme with small model railways is the “Inglenook” three sidings shunting puzzle. The intricacy of operating such a layout is determined as much by the length of the headshunt as it is by the number of wagons involved and the capacity of the sidings.
A fan of three sidings is not an unusual feature on real railways, but they are usually connected to the rest of the network and it is possible to pull all the wagons clear of the sidings if required.
The image below shows something much more unusual, if not unique. Note the red arrow, indicating the end of the headshunt, there is no connection to the outside world from this real life Inglenook.
The layout appears to hold half a dozen freight cars and a Trackmobile shunting locomotive.
Note there are also no loading or unloading facilities (apart from a rudimentary team track) because there’s nowhere to ship cargo to/from anyway, as is so often typical of this type of shunting puzzle in model form.
As a rough guess I’d say it’s some sort of training facility where people can get experience of shunting in a relatively safe environment away from running lines, but it just goes to prove that there is a prototype for everything.