From ancient mythology and folklore, we know that our Celtic ancestors worshipped trees long before science discovered the benefits they provide for the environment. Their respect for trees can be seen throughout history.  The first European alphabet, the Ogham alphabet, has every letter named for a tree or an important companion of trees. There are over ten thousand places in Ireland that contain a tree in their name.  This, of course, includes Kildare, Cill Dara, the church of the oak. In Celtic history the oak, ash and hawthorn trees were held as the most sacred.