From the Introduction:
The New World is the grave of Lemuria, the greatest of all nations. The barbaric tribes that live in the New World now walk upon its bones, the ruins of temples and palaces, ignorant of the wisdom and power buried beneath their feet. When colonists from a distant continent settle on the shores of the New World, whispers of Lemuria flutter through the winds. Adventurers from the colony find the ruins and marvel at their beauty. Scholars listen to the legends told by tribal elders and connect them to ancient stories of a lost empire. Native warriors and mystics commune with spirits awoken by the colony’s arrival. The Ruins of Lemuria stir the blood of the ambitious and curious. Soon expeditions will be mounted to crack open dusty tombs to learn their secrets and plunder their treasures. Little do these adventurers know that the doom that befell mighty Lemuria waits to greet them.
The Ruins of Lemuria describes a massive network of ruins that spread across the entire continent of the New World, the remnants of a powerful civilization more advanced in science and magic than any other in the history of the world. Fragments of their knowledge lie deep within the ruins, along with powerful magical items and vast amounts of treasure. Needless to say, if the knowledge or magic items are found and brought back to civilization, it could change the course of history. Lemurian magic and technology is still more advanced than anything else the world has ever known. A few adventurers armed with this power can end wars, curse diseases or doom their own civilization. Not only are the Ruins a perfect locale for a fantasy campaign, the implications of its rediscovery can also affect the world. The heroic player characters can use their findings to improve or even save the world. Of course this also means that others will vie for the power of the Ruins. This supplement provides a framework to incorporate the Ruins into most high fantasy RPG campaigns.