Some good examples of websites that provide maps of ley lines are Ancient-Wisdom.com and VortexMaps.com. Some people believe these lines are part of a world-wide energy grid, and maps of this grid are available on websites such as AncientExplorers.com.
The term "ley line" was coined in the 1920s by a man named Alfred Watkins. He proposed that some prominent stone features built into the British landscape were used by prehistoric societies for navigation along trade and ceremonial routes. Mr. Watkins attributed no mystical properties to these lines at the time, but over the years the mythology around them has grown in popularity. This mythology includes the concept that many ancient structures, Stonehenge and the Egyptian Pyramids, for example, are all connected by ley lines.