here is what it looks like from satellite view on Google Earth.
This was a common way to prevent riverbank erosion from flood waters, and these stacks of crushed junkyard cars are also known as riprap. America has them everywhere, Google Image search "cars on the river bank" and you'll see what a polluted river country we are. The Rio Grande, the Yellowstone River
this is in North Carolina, John the Carpet Bagger was out looking to find why some random cars were on a river bank, and learned all about the practice that is now around 50 years old. Big rocks must have been more expensive than just clearing out the junkyards of demolition derby dead cars. http://www.thecarpetbagger.org/2013/04/automotive-riverbank-preservation.html
and on the Bighorn River in Montana
about 4 bends of the river north of Ft Smith