Since so much of the Bible takes place in Egypt, why is there no mention of the pyramids? To this day we don’t know for sure how they were constructed, so why no mention of them?
Some of the pyramids surely existed during the time of Moses (around 1300 or so B.C.), but most of the time Israel that spent in Egypt was not spent near the Giza plateau, where the great pyramids are. The Israelites seem to have lived in Egypt’s northern grain storage cities, so Moses would have visited the palace in Memphis, which is not at the Giza plateau.

We also need to remember that the Israelites (including Moses) were nomads, not great building constructors, until well into their history. Such structures may not have impressed them very much. Remember the negative judgment passed on such human constructions in the early tradition about Babel (Genesis 11:1-9).
You may want to see the related Beliefnet article on recent archeological discoveries about the pyramids.
—Ben Witherington III