The blocks are real and visitable: remnants of Menkaure's upper (mortuary) temple, which carried granite casing over a limestone core, some core blocks estimated above 400 tons, with 24 granite pillars in its court. Mainstream dating puts construction in the Fourth Dynasty, reign of Menkaure, c. 2532-2503 BCE, with the temple finished hastily in mudbrick after his death. The extreme erosion of the granite itself is part of the record.
Ben van Kerkwyk's case, built with Christopher Dunn's analysis: the cornice and couch blocks show consistent radii, compound curves, and surface finishes comparable to modern profile machining, in Aswan granite, which ranks near the top of the hardness scale, and the claim extends to techniques used today to relieve stress lines. The conclusion drawn: a capability beyond dynastic hand tools.
The wider alternative frame: the pyramids' granite work predates the dynasties, inherited and reused by Old Kingdom builders who never matched it. Egyptology counters with an unbroken tool record, copper saws, tubular drills, and abrasives found in context, plus quarry marks and workmen's graffiti naming Menkaure's own crews.
Consistent radii and compound curves in the hardest common building stone on Earth: patience, or machine tools?