The Parkeisenbahn is Cottbus's narrow-gauge park railway, running for almost four kilometres through the green belt around Branitz Park and the zoo. Like many former East German park railways, it is both a family attraction and a working miniature railway with proper stations, signals, and seasonal services.
It is most useful if you are visiting Cottbus Zoo, Branitz Park, or the planetarium with children. Check the timetable before going, as service is concentrated in the warmer months and on weekends.