The Selketalbahn departs from a small station near the edge of the old town and heads south into the hills. The journey is genuinely enjoyable even if you are not a railway enthusiast — the Selke valley is wooded and quiet, the steam engine works visibly hard on the gradients, and the pace is slow enough that you actually see the landscape. Getting off at Alexisbad or Mägdesprung for a walk and catching a later train back is a popular approach.
Return tickets are affordable and the service runs year-round, though frequency drops outside summer. On busy summer weekends the trains can fill up; turn up a few minutes early for a window seat on the right side heading uphill for the best valley views. The combination of a morning on the Schlossberg and an afternoon on the Selketalbahn makes for an efficient day in Quedlinburg.