Writer's Breezeblock

Today's prompt was an interesting one (and I'm playing it fast and loose with the word interesting). Write about masonry. I resisted the urge to raid my many volumes of wall-related poems and somehow came up with something.

Things on Moors

Walls are strangely put together
Pulverised iron and lime, remade
into something that crumbles in time.
They can come apart at the seams
and still stand, tired and brow-beaten.
I have seen them on northern moors
with nothing even holding them
together. Just a pointless perimeter
between nothing and emptiness.