Have you ever heard of the La Brea Tar Pits? They are pits located in the Hancock Park area of Los Angeles that are famous for preserving prehistoric bones and animal parts. Well, we inspected a property not too far from those pits. With that being said, what you are seeing is natural oil and tar seeping up through the ground into this person's basement. Water was coming into the area and over time it brought the tar and oil with it. Nasty stuff.