Perhaps the earliest megalithic poem of them all -
The Ravager of the night,
the burner who has sought out barrows from old,
then found this hoard of undefended joy.
The smooth evil dragon swims through the gloom
enfolded in flame; the folk of that country
hold him in dread.*
* Beowulf. Translated from the Old English by Michael Alexander. Penguin Classics. ISBN 0-14-044268-5. pp122.