A minimal train service operates between Poprad (Slovakia) and Muszyna (Poland) just twice a day on weekends in the summertime and wintertime, but not in spring or autumn. But regional services operate all year round to Plaveč in Slovakia that is just 14.2km from Muszyna, and Muszyna is likewise served by passenger trains from towns in southern Poland all year round. There would be potential for a Košice – Nowy Sącz – Kraków long distance service.
What needs to be done: at the very least extend regional services to Plaveč as far as Muszyna all year round, to assess the potential for daily cross border journeys here
European Commission Analysis
In 2018 the European Commission published its “Comprehensive analysis of the existing cross-border rail transport connections and missing links on the internal EU borders”. The main report (74 pages, PDF) summarises the issues, and Annex 3 of the report (384 pages, PDF) analysed every single border.
For the sake of simplicity, I have made a PDF just of the relevant pages of Annex 3 that cover Plaveč-Muszyna – you can find that PDF here.
Photos from this location