Ogham inscriptions, often refereed to as beth luis nion, dates from the 3rd to 6th century AD and are found exclusively in celtic nations of the British Isles.

The script comprises an alphabet of twenty-five characters that were used for stone/wood inscriptions and divination.

Ogham has a powerful relationship with nature and trees in particular, representing a group of twenty trees that give their names to the letters of the ogham alphabet. It has been suggested that poetry involving trees of the ogham script was used to pass on secret knowledge and messages.