Pyramid of Djoser

29.8712°N, 31.2165°E.

Stepped funerary monument at Saqqara, the world's first known monumental stone building. Constructed approximately 2670 BCE for third-dynasty pharaoh Djoser by the architect-priest Imhotep, who was deified more than a millennium later for the achievement. Six retreating mastabas rise to a final height of 62.5 metres on a base of 121 by 109 metres, faced originally in polished Tura limestone. Beneath the pyramid extends 5.7 km of underground galleries, including the central burial shaft sunk 28 metres into bedrock, sealed by a 3.5-tonne granite plug. The complex is enclosed by a 10.5-metre limestone wall pierced by a single functional gate, with thirteen false doors carved into the perimeter to confuse the dead and the living. The blue-tile chambers reproduce in stone the reed-bundle architecture of the Nile Delta.

Imhotep invented monumental stone architecture in a single building, and Egypt copied his step-pyramid for fifty more years before figuring out how to make the sides smooth.