Museum Center, at the Cincinnati Union Terminal building, is the current home of the B&O outside third rail layout. There is also a huge display of Cincinnati in various time eras with S-scale trains running through it. As far as I know, Doug DuBay's layout is in storage. It was looking more and more run-down and in need of maintenance each of the last few years it was set up. Museum Center also has a toy train themed Holiday Junction display which typically contains early trains from Carlisle & Finch (a Cincinnati company), Lionel, Ives, etc.
Also open to the public is EnterTrainment Junction, which is a gigantic G-gauge display.
https://entertrainmentjunction.com/
Of course, if you come to Cincinnati, visits to my layout, Bill Bramlage's layout and possibly some others can be arranged.