Chessmen?

Village by the sand
hiding the ninety-one
pieces carved from ivory
brought in from across the sea

Men from the north
left them for us to guess
their play with the future
after they had gone from these shores

Leaving behind only names
for the villages along the shores
the hills, bays and inlets
no further trace was left

Except the ninety-one
in the sand by the village
along the bay that named a whole district
Were they chessmen?