Canyon Overlook at sunrise
In Canyonlands along the White Rim trail, I frequently looked at the surrounding cliffs and marveled, "what idiot put a road up THAT?".
Here some crazy idiots tried to build roads, I'm sure, straight up the cliffs, to terrify future travelers, but it was just too steep even for them. So they built this crazy ass tunnel 20 feet behind the cliff face on the left side. The tunnel is 1.1 miles long and curves to follow the cliff. It's narrow and drops several hundred feet along its length. Portholes were basted out in some places so you can see the facing cliffs as you drive through the darkness.
The rangers close the road to let RVs through in single file. Some RV pilots fail to straddle the centerline and shave the tops of their vehicles on the sides of the tunnel. You can see the scrapes.