The ancient rune-like writing system is carved into stones across Ireland.

On a hill above Ballycrovane harbour stands a tall, thin pinnacle of stone, standing over four metres high and clearly visible from the bay, as one sails from the open Atlantic into the safe haven located close to the Cork and Kerry border. Carved up the left-hand side is a dedication to an Irishman: MAQQI DECCEDDAS AVI TURANIAS, ‘belonging to Mac Deichet Uí Thorna’. The final two words identify this man as a descendant of Torna, which is possibly a reference to a long-gone local dynasty; the name is also found on four other stones in Kerry and Kildare and appears in later Irish genealogies. Early Irish law indicates that stones like this could be called upon to underpin a legal claim to land, while saga writers tell of long-dead heroes who, having fallen in battle, were buried beneath stones bearing their name. The archaeologist R.A.S. Macalister argued that this stone was originally erected as a prehistoric standing stone and that the inscription was added later – probably in the fifth century – after the invention of a form of writing known as ogham, created specifically to represent the Gaelic language.


http://www.historytoday.com/catherine-swift/story-ogham