Turtles have some hardcore armor. I was hoeing the ground in a thick patch of weeds and didn't see this turtle at all, until my ho slammed down hard on his back and clang off it like I'd hit a hollow rock. His head was still out and he looked at surprised as I was. A brown box turtle, just like I had in New Orleans when I was 11 years old (Tippy was it's name and it ran away during one of the many summer floods.)
In this very bottom picture you can see where I accidentally chinked it's armor, on the lower left hand side of the shell. Tough turtle... it waited for me to walk away before casually creeping off to a safer place.