North America
Great Allegheny Passage
The Great Allegheny Passage is a wonderful trail that stretches from Pittsburgh Pennsylvania to Cumberland Maryland. Much of the trail around Pittsburgh is paved, but most of it is a smooth double track. Much it is a converted railroad route along the Youghiogheny River, so the grade is easy and the scenery spectacular. Instead of riding up and down hills when crossing a valley, the trail has beautiful long bridges.
My favorite part of the ride was from Connellsville to Meyersdale, most of it heavily wooded. The trail from Meyersdale to Cumberland quickly crossing the continental divide, followed by a fast ride downhill and through some long tunnels to Cumberland. At Cumberland, the trail connects to the C & O Canal Towpath that continues on to Washington D.C.
For a one or two day ride, I recommend taking Amtrack to Connellsvile. You can ship your bike, or rent one there. There are plenty of places to stay and eat along the trail, so you don't need to carry equipment or food. The trail is especially beautiful around Columbus Day when the leaves are turning. Learn more about the Great Allegheny Passage here.