Narrow-gauge railways in Germany
A number of narrow-gauge lines survive, largely as a consequence of German reunification, in the former East Germany where some of them form part of the public transport system as active commercial carriers. Most extensive of those still employing steam traction is the Harz mountain group of metre-gauge lines, the Harzer Schmalspurbahnen.
Source: Wikipedia — Narrow-gauge railways in Germany (CC BY-SA 4.0)