The Vhnori had elaborate death rituals, based on the idea that the many naturally-occurring subspace vacuoles on their world could transport them to the Vhnori afterlife, called the Next Emanation. This practice would not only be applied to the dying, but also to people depressed or lonely. Furthermore, disabled Vhnori who were seen as taking up too much of their family's time and resources might be pressured ("out of love") to move on by said family.
Unknown to the Vhnori, the vacuoles actually led to a planet in the Delta Quadrant. On this planet, the bodies of their dead had been piling up for thousands of years, resulting in the only known concentration of the 247th element.
All this was discovered by Harry Kim of the USS Voyager when he was accidentally drawn through one of the vacuoles to the Vhnori homeworld in 2371. He returned using one of the cenotaphs, having seriously disturbed the Vhnori's faith. However, it was discovered that an unusual amount of neural energy existed in the planet's rings, perhaps implying that the Vhnori afterlife may not be completely without foundation. (VOY: "Emanations")