The only accessible trail in Shenandoah National Park
This trail was originally constructed through a virgin hemlock forest, but just as they were building it, hemlock woolly adelgids killed off nearly all the hemlocks (a few small ones live on). I didn't have the heart to visit for a few years after, but when I did I was pleasantly surprised - aside from the occasional enormous log, the aspect is not so much one of a dead hemlock forest as a young, living deciduous forest. There is a huge bank of mountain laurel at the beginning of the trail that must be just stunning if you catch it right - unfortunately, we never quite have (the picture of the mountain laurel in bud was taken on June 4, to give you an idea of when might be good to go). The trail also goes through a wetland (I've never noticed anything too unusual there) and over a small creek. In season, you can see cardinal flower blooming alongside the creek. I waffled between a 3 and a 4 on the rating because except for the mountain laurel, honestly, this trail does not have a lot of unusual features. However, the mountain laurel display is the sort of thing I would have hiked several miles to see when I lived in an area where they were less common.
The ADA slope guidelines changed after this trail was constructed, so there is a middle section that doesn't meet those standards. However, we have never had any trouble getting my daughter's manual wheelchair around the entire trail. There is a signboard by the parking lot that diagrams exactly where the slope exceeds the standard and by how much. The trail is packed fine gravel (crusher run, I think it's called?) and seems generally well-maintained - we visit at least a couple of times a year and have never had a problem with it being washed out. There are also a number of benches along the trail (the chains on them attest to the lengths that some people will apparently go to in order to get a free bench). This really is your best shot at getting out and enjoying being outside in nature while traveling with a wheelchair along Skyline Drive.