Some Challenges of Deep Mining † †This paper was written shortly after this author had presented a video lecture titled “Why rock mechanics and rock engineering?” at the invitation of the ISRM. The lecture addressed the more general topic of the importance of rock engineering in the 21st century, and may be of interest as complementary to this article. The lecture (~ 45min) may be heard at https://www.isrm.net/gca/?id=1309.