Soratami

The Soratami (also known as the Moon Elves or Shattered Elves) were an ancient "lost race" of elves who lived in the mountains in the southwest of Faerun.   The Soratami were an extremely advanced civilization, far ahead of their contemporaries, and in fact only recent break throughs have been able to replicate some of the tonal engineering feats (specifically, the sound order recognition system that has been implemented in nimblewrites). although many are familiar with their breakthroughs in engineering and technology, scholars have also pointed out that they were revolutionary in their stonework, metallurgy, architecture, mathematics, city planning, art, astronomy and astrology.   the Soratami are subject to one of the longest lasting mysteries on toril. 
"A race of stonecutters, artisans, and engineers. They invented machines and built elaborate underground cities where they researched powers to rival the gods themselves. And then, at a time we are still not sure when, they disappeared. The whole people, all at once. Leaving behind only their works." -Gerad Kinesward