The Sebilisian Empire was the first and greatest iksar empire to exist on Norrath. In the Elder Age, approximately 2300 years ago, the Sebilisian Empire rose. For nearly 750 years, they ruled most of Kunark.

At the height of the empire's power, many great cities and fortresses were built by the ancient iksar. The architecture was designed to instill fear in their enemies and defend against threats such as dragons and giants.
Structures in these cities were formidable and have withstood the test of time and extreme cataclysmic events. The creations of the Sebilisian Empire were many, but in the Age of Destiny, most had been swallowed up by the enviroment and lost to time. Thus the Great Sebilisian Empire fell into ruin.
Kor'sha is an ancient imperial iksar laboratory and experimentation facility. It is also the birthplace of the Sarnak race. The facility itself was a closely guarded secret, and only a very few iksar knew of its existence, let alone where it was hidden.
Because of its importance to the Empire, the construction of Kor'sha was of the highest craftsmanship, in order to ensure its continued service and operation. Thus, even though it is far older than many other structures in Kunark, it still looks much as it did in ancient times, with very little wear visible throughout the structure.