This tunnel at Robinson Creek KY (37.38180, -82.54229) was in the news in April, 2014, when two arsonists set the thing on fire.  The fire burned for weeks and the ceiling of the tunnel collapsed.  The arsonists were discovered and now face federal charges.
The tunnel is 700′ long and dates back 100 years.  It’s on an active CSX line that serves two coal mines.
Here’s what it looks like inside:

I’m told it took major work to get the tunnel back in operation.