In Slovakia, all students up to the age of 26 travel by train for free.

An excerpt from the article 37 facts about Slovakia

This program also applies to retirees (over 62 years of age), disability pensioners, and people on bridge pensions. This also applies to students and retirees from abroad. Moreover, along with free trains, the relief of commuting to work for other population groups was increased from 30% to 50%.