The railway station Canfranc in the Pyrenees was one of the biggest European railway stations, but closed since half a century, see here: https://en.wikipedia.org/wiki/Canfranc_International_railway_station
Only one rail is still in use for a regional train, the huge main building is completely closed up and can only be visited with guided tours. But the entire station area with the platforms, the rails and a lot of rotting cars is not too hard to access.

Rails to nowhere.