Why it matters
A royal estate on a knife-edge ridge, its mortarless walls fitted so finely they flex and resettle in quakes — drainage, terraces and astronomy without iron, wheel or mortar.
What mainstream says
Built under Pachacuti; accepted Inca engineering, extraordinary but understood.
Graded Grounded · A on the Ancient Code honesty scale (A grounded · C contested · S speculation · U unidentified). It belongs to the Impossible stone line of evidence.
Sources & further reading
The authoritative reference for this site/finding — and its own primary citations — so you can check us.