Bent Pyramid of Dahshur - Insights Into Egyptian Architectural History

What Does the 4,500 Year Old Bent Pyramid Teach Us About Architecture?

Bent Pyramid of Snefru, Dahshur Necropolis
Bent Pyramid of Snefru, Dahshur Necropolis; ruins of other parts of the complex are visible in the foreground. C. Sappa / De Agostini / Getty Images

The Bent Pyramid in Dahshur, Egypt is unique among pyramids: instead of being a perfect pyramid shape, about 2/3 of the way up, the slope changes abruptly. It is also one of five Old Kingdom Pyramids that retain their original form, 4,500 years after their construction. All of them--the Bent and Red Pyramids at Dahshur and the three Pyramids at Giza--were built within a single century. Out of all five, the Bent Pyramid is the best opportunity we have for understanding how architectural techniques of ancient Egypt were developed.


The Bent Pyramid is located near Saqqara, and it was built during the reign of the Old Kingdom Egyptian pharaoh Snefru, sometimes transliterated from the hieroglyphs as Snofru or Sneferu. Snefru ruled Upper and Lower Egypt between 2680-2565 BC or 2575-2551 BC, depending on which chronology you use.

The Bent Pyramid is 189 meters (620 feet) square at its base and 105 m (345 ft) tall. It has two distinct interior apartments designed and built independently and connected only by a narrow passageway. Entrances to these rooms are located on the north and west faces of the pyramid. It is unknown who was buried inside of the Bent Pyramid--their mummies were long ago stolen.

Why is it Bent?

The pyramid is called "bent" because of that steep change in slope. To be precise, the lower part of the pyramid's outline is angled inward at 54 degrees, 31 minutes, and then at 49 m (165 ft) above the ground, the slope abruptly flattens out to 43 degrees, 21 minutes, leaving a distinctively odd shape.

Several theories about why the pyramid was made this way were prevalent in Egyptology until recently. They included the premature death of the pharaoh, requiring the speedy completion of the pyramid; or that noises coming from the interior clued the builders into the fact that the angle was not sustainable.

The most common theory today is that a comparably sloped pyramid--Meidum, also built by Snefru--collapsed while the Bent Pyramid was still under construction, and the architects adjusted their building techniques to make the Bent Pyramid work.

A Technological Breakthrough

The Bent Pyramid's odd appearance provides insight into the technical and architectural breakthrough it represents in Old Kingdom monument building. The dimensions and weight of the stone blocks are much greater than its predecessors; and the construction technique of the outer casings is quite different. Earlier pyramids were contructed with a central core with no functional distinctions between casing and external layer: the architects of the Bent Pyramid tried something else.

Like the earlier Step Pyramid, the Bent pyramid has a central core with progressively smaller horizontal courses stacked on top of one another. To fill in the external steps and make a smooth-faced triangle, the architects needed to add casing blocks. The Meidum pyramid's outer casings were formed by cutting sloped edges on horizontally placed blocks: but that pyramid failed, spectacularly, its outer casings falling off it in a catastrophic landside as it neared completion.

The Bent Pyramid's casings were cut as rectangular blocks, but they were laid sloping inward at 17 degrees against the horizontal. That is technically more difficult, but it gives strength and solidity to the building, taking advantage of gravity pulling the mass inward and downward.

This technology was invented during the construction: in the 1970s, Kurt Mendelssohn suggested that when Meidum collapsed, the core of the Bent Pyramid was already built to a height of about 50 m (165 ft), so instead of starting from scratch, the builders changed the way the outer casings were constructed. By the time Cheops' pyramid at Giza was constructed a few decades later, those architects used improved, better-fitting and better-shaped limestone blocks as casings, permitting that steep and lovely 54 degree angle to survive.

A Complex of Buildings

In the 1950s, archaeologist Ahmed Fakhry discovered that the Bent Pyramid was surrounded by a complex of temples, residential structures and causeways, hidden beneath the shifting sands of the Dahshur plateau. Causeways and orthogonal roads connect the structures: some were built or added to in the Middle Kingdom, but much of the complex is attributed to the reign of Snefru or his 5th dynasty successors.

All later pyramids are also part of complexes, but the Bent Pyramid's is one of the earliest examples.

The Bent Pyramid complex includes a small upper temple or chapel to the east of the pyramid, a causeway and a "valley" temple. The Valley Temple is a rectangular 47.5x27.5 m (155.8x90 ft) stone building with an open courtyard and a gallery that probably held six statues of Snefru. Its stone walls are about 2 m (6.5 ft) thick.

Residential and Administrative

An extensive (34x25 m or 112x82 ft) mud brick structure with much thinner walls (.3-.4 m or 1-1.3 ft) was adjacent to the valley temple, and it was accompanied by round silos and square storage buildings. A garden with some palm trees stood near by, and a mud-brick enclosure wall surrounded all of it. Based on archaeological remains, this set of buildings served a range of purposes, from domestic and residential to administrative and storage.

A total of 42 clay sealing fragments naming fifth dynasty rulers was found in a midden east of the valley temple.

South of the Bent pyramid is a smaller pyramid, 30 m (100 ft) high with an overall slope of about 44.5 degrees. The small inner chamber may have held another statue of Snefru, this one to hold the Ka, the symbolic "vital spirit" of the king.

Arguably, the Red Pyramid could be part of the intended Bent Pyramid complex. Built roughly at the same time, the Red Pyramid is the same height, but faced with reddish limestone--scholars surmise that this is the pyramid where Snefru himself was buried, but of course his mummy was looted long ago. Other features of the complex include a necropolis with Old Kingdom tombs and Middle Kingdom burials, located east of the Red Pyramid.


The primary archaeologist associated with excavations in the 19th century was William Henry Flinders Petrie; and in the 20th century it was Ahmed Fakhry. Ongoing excavations are being conducted at Dahshur by the German Archaeological Institute at Cairo and the Free University of Berlin.


This article is a part of the guide to the Dynastic Egypt, and the Dictionary of Archaeology.

Aboulfotouh HMK. 2015. Astronomical algorithms of Egyptian pyramids slopes and their modules divider. Mediterranean Archaeology and Archaeometry 15(3):225-235.

Alexanian N, and Arnold F. 2014. The Necropolis of Dahshur: Eleventh Excavation Report Spring 2014. Berlin: German Archaeological Institute and Free University of Berlin.

Alexanian N, Lösch S, Nerlich AG, and Seidlmayer SJ.

2008. The Necropolis of Dahshur: Fifth Excavation Report Spring 2008. Berlin: German Arcaheological Institute and Free University of Berlin.

Belmonte JA, and Magli G. 2015. Astronomy, Architecture, and Symbolism: The Global Project of Sneferu at Dahshur. Journal for the History of Astronomy 46(2):173-205.

Krauss R. 1996. The Length of Sneferu's Reign and How Long It Took to Build the 'Red Pyramid'. The Journal of Egyptian Archaeology 82:43-50.

Mendelssohn K. 1971. A Scientist Looks at the Pyramids. American Scientist 59(2):210-220.

Mendelssohn K. 1973. A Building Disaster at the Meidum Pyramid. The Journal of Egyptian Archaeology 59:60-71.

Moeller N. 2016. The Archaeology of Urbanism in Ancient Egypt From the Predynastic Period to the End of the Middle Kingdom. New York: Cambridge University Press.

Müller-Römer F. 2008. A New Consideration of the Construction Methods of the Ancient Egyptian Pyramids. Journal of the American Research Center in Egypt 44:113-140.

Reader C. 2004. On Pyramid Causeways. The Journal of Egyptian Archaeology 90:63-71.

Rossi C. 1999. Note on the Pyramidion Found at Dahshur. The Journal of Egyptian Archaeology 85:219-222.