Great Allegheny Passage
In short
A 150-mile rail trail that runs between Pittsburgh, Pennsylvania and Cumberland, Maryland. It serves as a major route for cyclists and hikers across the Appalachian Mountains.
In plain words
It is a long, flat path built on old railway lines. People use it to ride bicycles or walk for many miles through scenic countryside. It connects directly to another famous trail called the C&O Canal towpath.
A simple example
A cyclist might start in Pittsburgh and ride all the way to Cumberland to meet up with hikers heading towards Washington, D.C.
Why it matters
It provides a safe, car-free way to travel through rugged terrain. It is a vital part of a much larger national network for outdoor recreation.
Easy to mix up
Do not confuse it with the C&O Canal towpath, which is a separate but connected trail.