Every visitor who goes inside the Great Pyramid of Giza walks in through the Robbers' Tunnel, a rough hole forced into the north face below Khufu's real entrance.

• ✓Wikipedia, Great Pyramid of Giza (Original entrance; Robbers' Tunnel; Descending and Ascending Passage)
• ✓Miatello 2010, PalArch's Journal of Archaeology of Egypt/Egyptology 7(6)
• ✓J. & M. Edgar 1910, The Great Pyramid Passages and Chambers

This ragged hole is how every tourist gets inside the Great Pyramid. Someone smashed it in. The real doorway is still there, about fifty-five feet up, under these giant stone chevrons. The hole is lower down: a rough tunnel hacked nearly ninety feet into solid stone. Tradition says it was dug around 820 AD, though it may be much older. Either way, the diggers were working blind. The builders had sealed the way up to the burial chambers. They slid three granite blocks down the passage, a stone far harder than the pyramid's limestone. The diggers couldn't break the granite. So they cut around it, through the softer limestone beside it. Those granite plugs are still there. The pyramid's lock has held for forty-five hundred years. Everyone just goes around it, starting at this ragged hole.