These are great for finding out where the trains actually go. And why there are some places that just don't show up on the usual sites.
Also I found that Rome2Rio is way to buggy to rely on. I keep reporting the problems of odd results and they keep telling me there are issues...
https://www.openrailwaymap.org/ You can zoom in to anyplace in Europe and see if train lines go there.
https://www.chronotrains.com/en You can use this to provide a graphic look to estimate times from any station to somewhere else, like to see where you can take a short day trip in X number of hours, up to 8 hours max.
https://direkt.bahn.guru/ This provides you a graphic of Direct Connections from any train station, with time it takes to get there
We are doing a 4 month trip around Europe next spring and these made planning the probable routes much easier to plan.
One such thing I found was we may end up in Tirano after coming down the Bernina Express, and all the routes from there went back to Milan, adding hours to get to our next stop either in Verano or Venice. But OpenRailwayMap showed me that I could take a 30 minute taxi ride (or 1 hour bus ride) to Edolo and train direct to the main line in Rovato, bypassing Milan and saving hours of sitting on a train.
-Bill