Homo naledi was a hominid that has recently made the news, in part because the discovery of a large number of fossils appears to suggest ritual "burials" by a species from 2.5 million years ago, significantly predating those of H. sapiens.
The "burial chamber" was found in a cave system at a depth of approximately 30 meters. Given that there should be zero ambient light at that kind of depth, it seems to me that either H. naledi was very strongly motivated to bury their dead in that particular location (which makes the burials even more amazing), or the chamber has changed it's depth and become significantly deeper than it would likely have been 2.5 million years ago.
Is it likely that a cave chamber can change it's depth significantly over 2.5 million years?
EDIT Added a view of the layout of the burial location cribbed from the New Scientist article... just because it shows how motivated H. naledi must have been to put their dead where they did.