Love them. Support them. Completed a 6 day bike trip from Pittsburgh to Washington DC on the GAP and C&O trails back in 2012. I would start as early as I could, often breaking trail for the day (wear a bandana and sunglasses or eat spiderwebs all day). Lots of deer and blue herons to hang out with. It was very peaceful and quiet, but I mostly remember green tunnel trails for most of the trip. There are wonderful stops and vistas along the way. As you leave the paw-paw tunnel, one of my favorite views of the valley quickly pass by, the closer you get to Georgetown, the better maintained the C&O is; the more beautiful the trail becomes.

I actually rode the C&O trail a bunch of times in Scouts and with my grandparents as a child. I think these are great for any skill level, including beginners. The biggest advantage for me is the fact there are very few roads you need to ride on. Because they are typically on old railways, or canals, they are usually not steep grades (though don't let somebody tell you "it's only a 6% grade!", because it sucks going uphill for lots of miles).

You can split up the trails in to day, weekend, or week-long trips. Especially on the GAP and C&O there are plenty of camps, towns and stops along the way to support yourself on the way. On my 2012 trip a guy caught up to me and tolerated my slowness for a bit. He was planning to finish the Pgh to DC trip in 3 days.

I've been contemplated riding the Erie Canalway, but my love for biking was ruined a bit with a bad case of achilles tendonitis after my last trip.

https://gaptrail.org/ https://www.canaltrust.org/plan/co-canal-towpath/ https://eriecanalway.org/explore/cycling