Long ago, my family and I travelled with a tent, and later on we carried the tent on our backs. I even got involved with a 4-H group and led some hikes. The Allegheny Plateau was one of my favorite destinations.
A railroad once built a viaduct over a deep valley there… a marvel of engineering at the time.
On one camping trip we visited the Kinzua Viaduct, and walked across it. Carol was terrified, both boys got a kick out of it. We even clambered down the steep hill to look at a couple of the foundation structures.
You could ride excursion trains across it.
When I was a student pilot, on one of the mandatory solo cross country flights I went to the airport near there. I asked the guy in the tower where it was. He told me it was near the outer marker. That would be right under me ;-(
It was impressive how it looked like a tinkertoy from a few thousand feet.
Years later a tornado knocked half of it down.
I will forever regret not taking one of those excursions.
Now it is just a fantastic lookout site. Allegheny-National-Forest-Visitors-Bureau
The inside info: at the turn of the (twentieth) century, they ran excursions over it too. They gave away salted peanuts for free. They sold lemonade for a price.
American ingenuity!