A real labyrinth?

Is there a real labyrinth somewhere?

By that, I mean something like a labyrinth house or something like that. There are outdoor mazes every now and then, but that's not what I mean. I mean something where you're in a building and there are lots of paths that all look almost the same, and you have to find a way out. It should take several hours, if possible, and it shouldn't be too easy.

Preferably something similar to the Backrooms:

Where you really have the feeling of being alone in a huge labyrinth.

Is there anything like that in Germany? I live in North Rhine-Westphalia, in the Ruhr region. If there's something like that nearby, that would be great, but somewhere else in Germany is also fine. Or maybe in a neighboring country like the Netherlands or something. Maybe we could plan something like that sometime.

Does anyone know anything like that? A truly gigantic labyrinth where you feel like you're alone. With liminal spaces and such. Like the backrooms. I definitely want to experience something like that.