This section is from the book "Ancient Legends, Mystic Charms, And Superstitions Of Ireland", by Jane Francesca Wilde. Also available from Amazon: Ancient Legends, Mystic Charms, And Superstitions Of Ireland.
The large old hawthorns, growing singly in a field or by an ancient well, are considered very sacred; and no one would venture to cut them down, for the fairies dance under the branches at night, and would resent being interfered with.
There is a Holy Stone in an island of the Shannon, called St. Patrick's Stone. It is shadowed by an aged hawthorn, the perfume of which can be scented far off on the mainland in the flowering season. At the top of this stone is a large hollow, always filled with water by the rain or the dew, which is kept from evaporation by the heavy shadows of the branching hawthorn. It is believed that the water of this hollow has great healing power, and sometimes when a patient is brought from a distance, a rude stone shed is built under the tree, and there he is laid till the cure is completed by the water of the Holy Stone. On leaving he ties a votive offering to the tree, which is always covered with these memorials of gratitude.
In autumn the people go to bewail the dead at St. Patrick's Stone ; and the mournful Irish chant may be often heard rising up in the still evening air with weird and solemn effect.