The Bent Pyramid, built under the Old Kingdom Pharaoh Sneferu (c. 2600 BC), is a unique example of early pyramid development in Egypt. It was the second Pyramid built by Sneferu.
The Bent Pyramid rises from the desert at a 54-degree inclination. Still, the top section (above 47 metres) is built at the shallower angle of 43 degrees, lending the Pyramid a visibly ‘bent’ appearance.
Location of the Bent Pyramid
The Bent Pyramid is an ancient Egyptian pyramid located at the royal necropolis of Dahshur, approximately 40 kilometres south of Cairo.
Overview
Archaeologists believe the Bent Pyramid represents a transitional form between step-sided and smooth-sided pyramids. Due to the steepness of the original inclination angle, the structure may have begun to show instability during construction, forcing the builders to adopt a shallower angle to avert the structure’s collapse. This theory appears to be borne out because the adjacent Red Pyramid, built immediately afterwards by the same pharaoh, was constructed at an angle of 43 degrees from its base. This fact contradicts the theory that the construction would take too long at the initial angle because Sneferu’s death was nearing. Hence, the builders changed their inclination to complete the building in time.
In 1974, Kurt Mendelssohn suggested the angle change have been made as a security precaution in reaction to a catastrophic collapse of the Meidum Pyramid while it was still under construction. The reason why Sneferu abandoned the Meidum Pyramid and its Step Pyramid may have been a change in ideology. The royal tomb was no longer considered a staircase to the stars; instead, it symbolised the solar cult and the primaeval mound from which all life sprang.
It is also unique amongst the approximately ninety pyramids found in Egypt in that its original polished limestone outer casing remains largely intact. British structural engineer Peter James attributes this to larger clearances between the parts of the container than used in later pyramids; these imperfections would work as expansion joints and prevent the successive destruction of the outer casing by thermal expansion.
In July 2019, Egypt decided to open the Bent Pyramid for tourism for the first time since 1965. The ancient formal name of the Bent Pyramid is generally translated as (The)-Southern-Shining-Pyramid, or Sneferu-(is)-Shining-in-the-South. Tourists can reach two 4600-year-old chambers through a 79-metre narrow tunnel built from the northern entrance of the Pyramid. The 18-metre-high “side pyramid”, assumed to have been constructed for Sneferu’s wife, Hetepheres, will also be accessible. It is the first time this adjacent Pyramid has been opened to the public since its excavation in 1956.
Interior passages
The Bent Pyramid has two entrances, one relatively low down on the north side, to which a substantial wooden stairway has been built for the convenience of tourists. The second entrance is high on the west face of the Pyramid. Each entry leads to a chamber with a tall, corbelled roof; the northern entrance leads to a chamber below ground level and the western to a chamber built in the body of the Pyramid. A hole in the roof of the northern section (accessed today by a high and rickety ladder 15 m (50 ft) long) leads via a rough connecting passage to the passage from the western entrance.
The western entrance passage is blocked by two stone blocks, which were not lowered vertically, as in other pyramids, but slid down 45° ramps to block the passage. One of these was lowered in antiquity, and a hole has been cut through it. A piece of ancient cedarwood propped up the other remains. The connecting passage referenced above enters the path between the two portcullises.
Construction phases
The Pyramid underwent three construction phases. In the first construction phase, a steep pyramid with a base length of 157 m and an inclination angle of approximately 58° (possibly even 60°) was planned. If the Pyramid had been completed in this form, it would have reached a height of around 125 m. Still, given the knowledge of ancient techniques and the comparison with completed pyramids, such a steep pyramid was probably not a realistic option. It did not exceed only a few stone layers. Due to the sound overall degree of preservation of the Pyramid, this phase can only be proven indirectly through offset points around 12.70 m from the lower descending corridor’s entrance and around 11.60 m in the upper descending corridor.
In the second phase, the builders reduced the inclination angle to 54°. This increased the base length to 188 m. Also, inclined wall layers were used as in the step pyramids because masons could not produce trapezoid stones at this phase. While step pyramids were built in ring-shaped shells of slant layers, the turn to undivided masonry made horizontal layers more practicable. If the inclination of 54° had been maintained, it would have reached a height of 129.4 m and a volume of around 1,524,000 cubic meters. The Bent Pyramid would, therefore, be the third-highest in the world. However, this inclination was not continued beyond a height of 49 m.
The masonry of this phase is faced with fine Tura limestone. In the third construction phase, the angle was reduced to 43° and, like in the Red Pyramid and all successive pyramids, the masonry was laid in horizontal layers. The slope reduction created a unique kink not found in any other pyramid. Due to the lower inclination angle of the upper part, the total height was reduced to 105 m. The total volume was 1,440,808 cubic meters. The upper area also has a cladding of fine Tura limestone.
Recent conclusions rather speak against a connection between the change in slope and structural defects. It isn’t very sure that a weight reduction was a relevant criterion for a structure of almost closed mass. The early decision against the 60° inclination initially envisaged suggests that geometric aspects were the decisive factor in the gradient change.
Following the assumption of tangential construction ramps inclined up to 10° as the simplest form of ramp, the fact edge lengths became smaller as the height increased made it increasingly difficult to keep the gradient low. This could be compensated for by reducing the ramp width to around 3 m, which was sufficient for pairs of train crews, but even for such narrow ramps, the geometric volume could not provide enough space when the gradient was too steep. Models and abstract calculations were not possible at that time. It must, therefore, have become apparent to the construction managers halfway up that ramp structures would not be feasible when maintaining this gradient. All completed pyramids (first the Red, then the Great Pyramid) never exceeded the maximum gradient of 53°.
Causeway
A causeway leads from the Bent Pyramid northeast toward the Pyramid with the valley temple. The causeway was paved with limestone blocks and had a low limestone wall. There may have been a second causeway leading down to a dock or landing stage, but no excavation can prove this assumption yet.
Artificial landscape
As the world’s first geometrically “true” Pyramid, the Bent Pyramid is unique in its construction method and manifests through the surrounding landscape. Nicole Alexanian and Felix Arnold, two distinguished German archaeologists, provided new insight into the meaning and function of the Bent Pyramid in their book The Complex of the Bent Pyramid as a landscape design project.
They noticed that the sites of the Bent Pyramid sit aside in the middle of a pristine desert area instead of a fertile region near the Nile River like all the other pyramids. After a long period of detailed investigation, they believed the Bent Pyramid’s landscape was, in fact, artificial. When the archaeologists observed the landscape closely, the pyramid plateau seemed levelled artificially, and nearby escarpments and trenches were all made by human beings.
Moreover, a few traces indicated a build-up of the garden enclosure. The impact of humans on the landscape is also represented by a wadi canal connecting the Bent Pyramid to a harbour, which shows a distinct difference between the southern and northern sides of the canal. It offers a substantial difference in level concerning the finding. The slope of the channel of south Wadi seemed to have been rectified when the archaeologists compared it to the natural and twisted northern side. Arne Ramisch supported this idea by providing evidence that displays a low correlation between fraternal patterns of the channel and natural topography in the environs, which is the southern side of the Wadi of the Bent Pyramid.
The purpose of this artificial construction might hold mythical meaning and ritual function. Based on available evidence, garden enclosures and water basins are both the counterparts of funeral rites, which indicates a regular practice of rituals at Dahshur. However, another implication states that the garden closure helps create a suitable living environment in the desert. The levelled plateau, the quarrying trenches on the western and southern sides of the Pyramid, and the nearby smaller tombs emphasise the Bent Pyramid’s monumentality, aided by its long distance from the surrounding structures. These features represent the imprinting social hierarchy in creating this landscape, which means the power of the Egyptian King at that time. Alexanian and Arnold describe this construction concisely: an artificial mountain erected within a contrived landscape.
Satellite pyramid
A satellite pyramid, suggested by some Egyptologists to have been built to house the pharaoh’s ka, is 55 metres (180 ft) south of the Bent Pyramid. The satellite pyramid measured initially 26 metres (85 ft) in height and 52.80 metres (173.2 ft) in length, with faces inclining 44°30′. The structure is made of limestone blocks, relatively thick, arranged in horizontal rows and covered with a layer of fine limestone from Tura. The burial chamber is accessible from a descending corridor, with its entrance located 1.10 metres (3 ft 7 in) above the ground in the middle of the north face. The corridor, inclined at 34°, measured initially 11.60 metres (38.1 ft) in length. A short horizontal passage connects the corridor with an ascending corridor, inclined at 32° 30′, leading up to the chamber.
The design of the corridors is similar to the one found in the Great Pyramid of Giza, where the Grand Gallery takes up the place of the ascending corridor. The corridor leads up to the burial chamber (called this even though it most probably never contained any sarcophagus). The chamber, located in the Pyramid’s centre, has a corbel vault ceiling and includes a four-metre deep shaft, probably dug by treasure hunters, in the southeast part of the chamber.
Like the main Pyramid, the satellite had its altar with two stelae on the eastern side.
