 The full running line of 3.95 kilometres is marked throughout at 100 metre intervals with white-painted stone mileposts.Although there is no 'true' terminus station, as both ends of the line feature return balloon loops, Prater Hauptbahnhof and Rotunde were originally built to serve the two ends of the original (shorter) railway.When the line was extended to the Ernst-Happel sports stadium in 1933 a new 'terminus' was constructed.