Constructed during the early part of Sneferu’s reign, the Bent Pyramid is the second of his three major pyramid projects and is widely regarded as a key evolutionary step in pyramid architecture. Unlike later true pyramids with continuous straight slopes, the Bent Pyramid features a marked change in angle—starting at approximately 54° and shifting to 43.5° about halfway up. This deviation has generated substantial academic debate regarding its cause, ranging from structural instability to symbolic design or mid-construction modification. The Bent Pyramid is notable for its unusually well-preserved casing stones, particularly on the lower portion, and for retaining both of its internal burial chambers—rare survivals among Old Kingdom pyramids.

The Bent Pyramid represents a significant architectural experiment and marks a critical point in the development of royal funerary architecture, directly succeding the Black Pyramid of Meidum and preceding the construction of the Red Pyramid—Sneferu’s next and final pyramid, which successfully realized the full smooth-sided form.

circa 2570 CE

Exterior
The pyramid originally stood at a height of approximately 104.7 meters, with a base measuring about 188.6 meters on each side. Its most distinguishing feature is the visible break in slope: the lower portion rises steeply at an angle of 54°31′13″, while the upper section ascends at the shallower angle of 43°21′. The change occurs around 47 meters above ground level. The reason for this adjustment remains contested. Some scholars argue it was a precautionary correction after discovering cracks or settling in the lower structure, while others suggest the original plan always included the angle shift to ensure stability or to meet time constraints.

The outer casing, made of fine white Tura limestone, remains largely intact on the lower half, making the Bent Pyramid one of the few pyramids in Egypt that retains much of its original casing. This offers valuable insight into the appearance of pyramids as completed monuments rather than as the stripped-down cores visible today. A satellite pyramid stands on its southern side, featuring its own small burial chamber and corridor system.

circa 2570 CE

Interior
The internal architecture of the Bent Pyramid is notably complex and atypical for the period. It features two independent entrance corridors: one on the north face (at around 12 meters above ground) and another on the western face (at around 33 meters high), each leading to separate internal chambers. The northern descending corridor extends down to a rectangular corbelled chamber beneath the pyramid’s core, while the western passage leads to an upper corbelled chamber positioned directly above the lower one.

Both chambers exhibit corbelled vault ceilings constructed with limestone courses, intended to relieve weight and prevent collapse under the pyramid’s mass. A narrow connecting tunnel—likely excavated after initial construction—links the two chambers, suggesting a later phase of internal modification or adaptation. No sarcophagus has been found in either chamber, and no inscriptions naming Sneferu have been recovered from within the pyramid itself; however, adjacent inscriptions and archaeological context confirm his association with the monument.