The following is a compendium of knowledge regarding some of the numerous tombs of ancient Sith to be found on Korriban. The compendium is not freely distributed over the holonet, but can be found by those who walk in the shadow.
I
Valley of the Dark Lords
The most infamous and well-documented tombs of the ancients are located in a central valley immediately outside of the Sith academy, to the south. This valley, known as the Valley of the Dark Lords due in part to unusually high concentration of tombs in such a relatively small space, is home to the tombs of Naga Sadow, Ajunta Pall, Tulak Hord, and Marka Ragnos. It is suspected, and indeed very likely, that there are more tombs located in or near this valley because of its historical and cultural significance to the Sith (both the order and the species); but Korriban has not been subject to many excavations in recent years, and they remain lost to us even now.
It goes without saying that as time passes and legends live and die, more tombs will be erected in the Valley of the Dark Lords. The significance of this location cannot be understated; in many ways, it is the heart of the Sith moreso than even the academy. For after all; academies can be replaced. The legacies of the ancients cannot. At the same time, it would be incorrect to assume that there are no tombs elsewhere on Korriban, and only a fool would dismiss these examples as belonging to the weak or worthless simply because of their location. While the Valley of the Dark Lords is a tradition for many of the most respected and feared of the ancients, there are some who wished for their final resting place to be away from the shadow of another.
//Work in Progress. Will update.