Did you know there are more options for border crossings than maps and timetables will tell you? If the timetables doesn't show them, it might be because it deems the distance to the stations on either side of the border too far. But if the alternative is a full-day detour, then consider this:
Italy-Slovenia
The stations of Gorizia (Italy) and Nova Gorica (Slovenia) are not connected but are only 3,5km apart. This border crossing comes in addition to the only alternative one at Trieste.
I did this walk on a Sunday morning and was prepared for dullness and emptiness, but instead found no less than 20 coffee bars with the locals enjoying dolce with their morning sip.
Hungary-Slovakia
The stations of Sátoraljaújhely (Hungary) and Slovenské Nové Mesto (Slovakia) are connected by rail but only freight trains use them. However the two stations are only 2,5km apart, leading you through the small town of Sátoraljaújhely which I found a lovely stop and with plenty of options to stay, shop and eat. This crossing comes in addition to Hidasnemeti-Kosice, which is only crossed by Eurocities with the downside that these have a compulsory reservation. Apart from the cost, they also take away the spontanity of rail travel with a pass.
Slovakia-Poland
There is only a seasonal (summer and winter, not in spring, neither in autumn) train connection between Slovakia and Poland, in weekends, crossing the border near Circ. I was there in May, so out-of-season and the beforementioned connection wasn't advertised yet. But when searching through old rail maps and Google Earth it did strike me that the rails were there, and also that Google mentioned the connection.
Details about the seasonal connection, called Beliansky Express, are eadvertised here:
https://www.zssk.sk/en/train-connection-poprad-tatry-muszyna/
As Muszyna is a dead end line, to cross the border you need at least these two legs:
- Poprad-Tatry to Muszyna
- Muszyna to Tarnow
But there is a catch: once in Poland, there is no onward train from Muszyna but a replacement bus! (I don't know if this is temporary or permanent)
When I went from the Slovakia to Poland in May 2023 the seasonal train wasn't there and I had seen the onward train was a replacement bus. Hence I took the more easy connection of travelling by Flixbus from Bardejov to Krakow. It was simple, faster than going all the way through Czech Republic, not expensive, the same fantastic views ... but it wasn't a train.