Sin-thé-byant (Dead Elephant's Pit) is the main cave of Pyaung-pyin
and it is in fact a mammal cemetery.
In the past rubies
and other gems have been recovered just beside the remains of the dead mammals. Some of these rubies are said to be large and of fine quality. In the mid-1990s the entrance to the cave was blocked by small boulders and in November 2003 no gem mining took place here.
Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 233