Dragons Teeth WWII what were they made from?

[ericmark]

The three near to old railway line, now the Mawddach Trail seem to be concrete as I would have expected, but outer two seem to be slate. Also, this is halfway along the Mawddach trail so would have expected any anti-tank before this point. Any ideas?

 

[JohnD]

Made of whatever they could lay their hands on.

A lot of British wartime concrete was terrible quality.

The West Wall was not.

 

[Highway Man]

The reason why they look like slate was probably because there would have been an abundance of slate to use for either shuttering or mixed into the concrete. Often WW2 concrete was made with cobbles and sand off beaches so was ruff stuff. Does the trail taper off further down the way or perhaps was fortified by other things, such as military camps or perhaps no landing points further down and this was the first position close to the landing points?