Back in my hometown of Brixham, Devon, England, there was this old bridge that used to have traintracks going over it. The tracks had long since vanished leaving just the bridge which was deep and made of grey stone that was blackened underneath. It was flat on top, and arched underneath like the top of a basketball. The roof was quite low to the ground where the road went under it.
I had never seen anything but there had been many, MANY strange sightings of a ghostly huge black dog that would watch cars driving underneath sometimes, and even run out of one wall into the car, dent the car and fall over dead. When the person got out of the car, they would see a huge dent on their car hood with black shorched claw marks, but no sign of any animal.
Rumour had it that back in the late 1940's when the tracks were still in use a great dog had been crushed by the train on the tracks going over the bridge.
My Dad showed me once huge scratch marks on the walls under the tunnel. That was enough to make me not want to go back there.