At the necropolis of Dahshūr, an ancient Egyptian burial site on the west bank of the Nile, stands an odd-looking pyramid dating back some 4,600 years. Known as the “Bent Pyramid” because it boasts a peculiar double slope, the structure represents a pivotal moment in Egypt’s architectural history, when the ancients were transitioning to the straight-sided pyramids that are iconic today.
The Bent Pyramid has not been accessible to the public since 1965, as Live Science’s Laura Geggel reports. During the intervening decades, the 331-foot-tall structure underwent much-needed restoration work; experts fixed up internal and external stairs, added a lighting network and repaired stone work in the corridors and chambers. Thanks to their efforts, tourists can now enter a raised entrance on the newly reopened pyramid’s northern side, climb down an 86-yard tunnel and explore two chambers, according to Reuters’ Aidan Lewis.
Sneferu, a pharaoh who ruled over Egypt in the 25th century B.C., commissioned the pyramid, which was the first to be built at Dahshūr. It appears “bent” because its slope changes at the mid-way point; the lower part of the pyramid was built at an angle of 54 degrees, but the top part clocks in at an angle of 43 degrees. Mostafa Waziri, secretary general of Egypt’s Supreme Council of Antiquities, tells Lewis that the architectural direction shifted because cracks began to appear in the structure, indicating that it was unstable.
The Bent Pyramid may represent one step in Sneferu’s journey to find the perfect pyramid formula. Salima Ikram, an Egyptologist with the American University in Cairo, tells Robyn Bresnahan for the CBC that the pharaoh had four pyramids built on his behalf; while it’s not entirely clear why, experts think he “might have ... been trying to get it right,” Ikram says.
The first was constructed at the site of Meidum, and it was originally a stepped pyramid—but, according to Encyclopedia Britannica, Sneferu later ordered that the structure be modified to form a “true,” or smooth-sided pyramid. The Meidum pyramid, however, “had [a] really acute angle and didn't work out so well,” Ikram explains. Next, Sneferu turned his attention to the Bent Pyramid at Dahshūr, which represented the first attempt to build a true pyramid from scratch, but which also ran into problems. According to Ikram, Sneferu subsequently built a third, smaller pyramid, with his efforts finally culminating in the Red Pyramid at Dahshūr—a red limestone structure with smooth sides and a 43-degree angle.
This pyramid, Ikram says, “was perfect.”
Experts don’t know where Sneferu was ultimately buried. “Maybe in this [Bent] pyramid, who knows?” says Mohamed Shiha, director of the Dahshur site, per Lewis.
In addition to opening the Bent Pyramid, Egyptian officials have also re-opened an adjoining, 59-foot “side pyramid,” which may have been built for Sneferu’s main wife, Hetepheres. Khaled al-Anani, Egypt’s Minister of Antiquities, also announced that archaeological work near the Dahshūr pyramids had unearthed masks, tools and coffins, some of which contained well-preserved mummies.
“[T]hey’re opening up new sites that have never been opened properly for tourists before,” Ikram tells Bresnahan. “Apart from a few archeologists, no one’s really been in there for the past 80 to 90 years. So it really is quite something.”