Caves of the Dead
The Caves of the Dead are a collection of caves, caverns, tunnels and so forth in which the cryogenically preserved bodies of fallen Stenza (as per unerary protocol) are laid to rest.
Caves and tunnels have been used for this purpose for millions of years, as indicated by the remains of Proto-Stenza specimens found in such locations, often with marks on the scruff of the neck indicating that some other individual carried the deceased to that particular point to be interred. This is one of the marks that suggest that some form of intelligence or Collective Knowledge has existed among the Stenza and adjacent species for far longer than once thought.
History
Most remains of Proto-Stenza are found in caves in the mountains surrounding the Ice Flats, invariably facing out toward the Frozen Wastes. There are gaps in the data but transitionary forms have been found in other caves, allowing modern Stenza to piece together the more recent stages of the path from Proto-Stenza to modern Stenza.
There are two key events which pushed burial beyond merely the rim surrounding the Ice Flats. The first is the development of settlements, which helped delineate a space for the living, and its opposite, a space for the dead. The second, and arguably a closely related development, is the widespread idea that the Snow Warrior guarded the dead and that special permissions must be sought (customarily by pouring libations) in order to enter his realm to bury the dead (later expanded to engaging in other liminal professions such as metalworking). These libations have remained a central part of burial practices into the present day.
The collection of caves, caverns, and networks which house the dead have expanded over the centuries, encompassing several billion bodies preserved in tubes of ice and more or less divided up by Droga. (It should be noted that many of those killed in the Clan Killings had to be retrieved from the Ice Flats in order to be properly interred. It is unfitting and potentially dangerous to leave a corpse in a body of "water" called The Center of Life for too long.) No one knows exactly how many caves there are across the Frozen Wastes, but the truth is that Stenza will continue to die, and need to be buried.
This is really interesting - I guess there would not be much decay in the frozen land of the Stenza, so I'm guessing most of the bodies are really well preserved.
They are also deliberately cryopreserved. If nature will do it for you you may as well improve on the process. (Some of the earliest mummies were just poor sods buried out in the dry desert sand before being deliberately wrapped up and dried out and stuff like that.)