An old prophecy tells of secret inscriptions in Ogham (commonly referred to as the Celtic Tree Alphabet), visible only under a full red moon once every 300 years on the edge of two monoliths, providing unlimited access to the elementary realm of Water.
"Wisdom hides in secret places."
The monoliths are located at the coast nearby Siniu Fedhaib, in the forest of Caer Mna
"The ancestors walked the way before you."
Corwyn the Hunchback, studying the Ogham carved on the edge of the monolith
The power of Ogham, also referred to as the "Dark Speech", represents a key to a gate of parallel knowledge, significations and associations. Only individuals familiar with a vast range of knowledge of secret references can interpret this profoundly magical and complex system of correspondences, as a mean of conveying esoteric wisdom among initiates.
Orhain the Erudite and a few of his warriors
Citations and inspiration from "The Green Man Tree Oracle" by John Matthews & Will Worthington, a Connections Edition, 2008