Dimensions of Pila Muralia?

[Tim Edwards]

My own (admittedly bad!!) attached pictures from Aalen and the Saalburg

Although I like the caltrop arrangement, reenactors often set them up poorly, and my own group is equally as guilty.

If they are to be effective, they need to be almost half buried. Otherwise a well planted size 10 boot in the crux of the stake junctions could send them flying into the faces of the unfortunate legionaries sheltering behind!!