Ogham

Ogham (/ˈɒɡəm/; Modern Irish or ; Old Irish: ogam ) is an Early Medieval alphabet used primarily to write the early Irish language (in the 'orthodox' inscriptions, 4th to 6th centuries AD), and later the Old Irish language (scholastic ogham, 6th to 9th centuries). There are roughly 400 surviving orthodox inscriptions on stone monuments throughout Ireland and western Britain; the bulk of which are in southern Munster. The largest number outside Ireland are in Pembrokeshire, Wales.