Bent Pyramid

29.7903°N, 31.2092°E.

Second pyramid of Sneferu, at Dahshur, dated approximately 2600 BCE. The lower section rises at 54° for the first 47 metres and then bends to 43° for the remaining 58 metres, producing the distinctive concave-profile silhouette. The change of slope is conventionally read as a mid-construction correction after structural cracking forced the builders to reduce the load. Original height: 105 metres. The Bent Pyramid is the only Egyptian pyramid to retain most of its outer Tura limestone casing, giving an accurate impression of the original surface finish — bright white in the desert sun. Two separate burial chambers, accessible via two independent passages, have been excavated; both were found empty.

The Bent Pyramid's geometry is unique among the seventy-two pyramids of Egypt — and its limestone face has not slipped in four and a half thousand years.