Dragons, while commonly thought of as fire-breathing marauders, were, to the Celts, indicators of places of great power. Where dragons trod, mystic energy flowed, and where they laired were invariably places of great sanctity and mystical harmony. While dragons were dangerous, they were also indicators of fertility, of life. ‘The Path of the Dragon’ was the Celtic term for ley lines.
By Tim Lazaro (http://ezinearticles.com/?Dragons-Celts-and-Druids&id=2503264)