I FOUND A HIDDEN UNDERGROUND SIDEWALK - Adventure's of a Surveyor

I was mapping a roadway and drain crossing for future construction and found a sidewalk and railing inside the culvert crossing. I'm guessing it was intended to be a pedestrian crossing at one time but just never completed.
GoPro 5 Black
GoPro HD Hero (original)
Canon HF R500
iPhone 8
Snowmobiler
Off-Roader
Hunter
Fisherman
Outdoorsman