This road was rarely taken out of necessity. It's a scenic route, flanked by trees on both sides. We would take it on Sunday drives, fun outings sometimes culminating in visits to the cemetery where my family is buried. It was a tradition that whenever we went through the tunnel we would beep the horn to hear it echo.
For as often as I traveled this road as a child, I rarely took it as an adult until a few years ago, when I realized it was a convenient shortcut on my commute to work. Traffic and road conditions are inconsistent enough that I never trusted it on the drive in, but it was a fun and nostalgic route to take on the way back. And sometimes the afternoon sun would light up the trees in a way that was simply amazing.
The first three photos show the view after you go through the tunnel from the Sans Souci side. I don't know if this was a foot bridge, a rail bridge, or some other sort of bridge.
The next two shots are the view of the same bridge from the other side. I had to step out of the road while taking these images so several construction vehicles could rumble past.
Here is the tunnel seen from the south side looking towards Sans Souci. I took this from a side road into a small housing development - a relatively safe spot to take a photo of a tunnel.
UPDATE, November 16, 2017: Some historical background from Jared Whittaker, via Facebook:
That Tunnel along with the bridge were built by the Delaware, Lackawanna and Western Railroad as part of their Hanover and Newport Branch Line. Trains used to come across a bridge from the Bloomsburg Branch of the DL&W which ran along the river from Scranton to Sunbury. Passing through most towns on the West Side. The Newport and Hanover Branch served the DL&W Coal Breaker in Nanticoke and Hanover Twp. These breakers were The Bliss, Loomis, Truesdale and Auchincloss. The line that ran over this bridge came from The Loomis and went to the Bliss and Truesdale Breakers. Another line went over the tunnel on Dundee Road and served the Auchincloss with Road crossings at Kosciusko St and Prospect St. Sad to see history being destroyed.