Pošumavská Jižní Dráha / Böhmerwald Südbahn
This is claimed to be the shortest international railway in the world, at 105 m long. Called "Pošumavská Jižní Dráha" or "Böhmerwald Südbahn", it is located at the border between Czech Republic (Nové Údolí) and Germany (Haidmühle), in the "no-mans land" between the two border posts - the German border hut can be seen in the picture.
Part of the line (!) is on the alignment of the closed railway route between Nové Údolí and Haidmühle. Nové Údolí ČD station is nearby.