The riddle of the inscriptions at Newgrange, Knowth and other equally ancient Irish sites in the Boyne Valley has been deciphered at last.

The 3500 bc petroglyhps describe the oldest calender in the history of mankind. The inscribed passage mound stones tell of prehistoric man's concept of the world: the flat earth with a hemispherical bowl overhead, the sun and the moon circling round.

The legends and myths of Ireland can be directly related to these stone engravings, and in this book Neil Thomas has endeavoured to recreate in his mind the ways in which early man would have thought and acted.