The Walls of Sacsayhuamán
Above Cusco, Inca walls are built from stones weighing many tonnes, cut to fit so tightly that a knife blade won't slip between them.
What was reported
Sacsayhuamán is a walled complex on a hill above Cusco, the old Inca capital. Its three zigzag terraces are built of enormous limestone blocks, the largest estimated at more than 100 tonnes, fitted together without mortar in irregular shapes that lock like a puzzle.
Spanish chroniclers were astonished by it, and some modern writers have claimed the stones must have been shaped by lost technology or visitors from elsewhere.
Explanations offered
Archaeologists have found Inca quarries, ramps and stones abandoned along the routes, and experiments show the blocks could be shaped by pounding with harder hammerstones and fitted by repeated trial and grinding. The tight joints and slight inward lean also make the walls resistant to earthquakes.
- When
- Built in the 1400s
- Where
- Cusco, Peru
- Witnesses
- Spanish chroniclers, and visitors ever since
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.