I do remember a scenario where you are given instructions to turn your engine and others where in order to go to a destination and connect a consist to the rear of your locomotive where it was inferred that you needed to use a turntable to complete the task. That is far as my memory works. I can't remember if it was a scenario I created or a workshop item. You could always build your own or edit a free roam.
There's many. Doncaster Works I think, Taurus Mountains, Falmouth Branch, Nottingham Netherfield... (browsing through my memory)
Donner Pass and Sherman Hill come to mind. Never actually used these as they don’t appear in scenarios. They may not even work. There is also one in Rascal and Cottonwood (not a real route). Respectfully
Yep, Donner Pass even has one underground (probably from the cold war ) See below old screenshot from the year 2012 Still hoping there is an official scenario for one of the US routes.