The Age of Reason
Many ruins dot the land of Drathl, while many of these are of past civilizations of Humans, Fyardh, and Dwarves from the Great War, there are those that are strange and much, much older. These ruins, made entirely of metal, often guarded (at least, according to the stories) my strange mechanized metal men, are all that is left of the Tessarids. The actual name of this ancient race is unknown, but they are called thus because of of a symbol that frequently appears in their ruins.
This symbol is a Tesseract, a mathematical and geometrical concept, sometimes known as a Hypercube of 4 dimensions. Here is another version, of 5 dimensions:
Little is known about this civilization. However, their language was cracked by Rodi Windswallow, who wrote one of the most complete studies of the Tessarids based on his study of the ruins known as Aki’Aul before they were all but destroyed by the dragons. Even so, what few intact writing samples that have been uncovered still tell little about their culture or their purposes. All that is known is that they were the cause of the last Reckoning, according to legend they started a war against the Dragons, and lost.