Sakethan burial mounds are ancient burial place where many Vulcan dissidents, known as the Sakethans, were placed following their deaths. Burial mounds have been discovered on several planets across the Alpha and Beta Quadrant's, including Calder II (and, at least in the mirror universe, New T'Karath).
At least in the mirror universe, the outside of the mounds were engraved with the inscription which translates as "Go no further, 'lest Mind and Body part for all time". Inside the chamber, a number of lirpa's were hung along the walls as a warning, and traps were placed inside to protect the person or items interred inside.
In the mirror universe in September 2371, Jean-Luc Picard discovered a remnant of the Stone of Gol located in a burial mound on New T'Karath. (TNG novel: Glass Empires: "The Worst of Both Worlds").