Originally Posted by wilkinsonk
Or the old-school kind...you can still find these on old battlefields in Europe. If you're ever on the North Shore of Oahu you can see some of these on the reef off of Aweoweo Beach Park as engineers practiced placing beach obstacles there during WWII.
I'm guessing that both of these would be !!
on a roadbook.
Wow, very cool. I think they call the one above a dragons tooth.