Yes railway ties from an old railway. The cement blocks at my back door are held in place by railway ties, they are also used as borders on the flower beds. Sometimes the kids sit on the step (railway tie). It was t a huge pile of tar, just a little spot. They are old and weathered ties. It's my yard and how it is.

There are so many cancer causing things around us. I am sure their exposure to the chemicals in my ties are next to nil.