East Broad Top Railroad is the oldest narrow-gauge railroad in the United States. You can visit the original shop and roundhouse where trains are repaired and stored and take a trip on the railroad.
If you go:
Train and tours operate seasonally so check website for times.
Links:

421 Meadow Street
Rockhill Furnace, Pennsylvania 17249 USA
info@eastbroadtop.com
Phone Numbers:
office
+1 (814) 447-3285
+1 (814) 447-3285