system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are we STILL discovering Egyptian pyramids, shouldn't these giant structures all be discovered by now?

In the news today, a new pyramid was discovered.  I can see new tombs being uncovered, but this thing is out in the open, why did it take so long to find?
gpt
Sand dunes buried most of them.   All the ancient Egyptians were dead by then and the area wasn't that populated, so people lost track of where they all were.

Sometimes the wind blows the sand away, and poof, there is the top of a pyramid.