Around 2600 BC, the Fourth Dynasty pharaoh Sneferu set out at Dahshur to replace the stepped pyramids of rulers like Djoser with a true smooth-sided pyramid, reflecting a shift toward the solar cult and the benben mound of creation. His builders began with a 157 meter base and a slope of 58 to 60 degrees, then widened the base to 188 meters and dropped to 54 degrees with inward-leaning layers. At about 49 meters they switched to 43 degrees and horizontal courses, creating the famous bend and a final height of about 105 meters. Physicist Kurt Mendelssohn argued in 1974 that builders panicked after the collapse at Meidum, citing cracked blocks and cedar beams inside. Researcher Tom Lyerman instead argues the steep top ran out of working space for ramps and sleds.

The Bent Pyramid keeps much of its white limestone casing. Engineer Peter James suggests looser joints acted as expansion gaps against desert heat, and NMR studies suggest the casing may be an early cast material bound with diatomaceous earth from the Faiyum. Inside, two separate entrances lead to corbelled chambers over 17 meters high, sealed by portcullises that slid down 45 degree ramps. Quarry graffiti names Sneferu, yet no sarcophagus was found. He then built the Red Pyramid at 43 degrees, the first successful true pyramid, laying groundwork for his son Khufu.

• A 79 meter descending passage, closed for over half a century, reopened to tourists in 2019
• A 4,600 year old cedar beam still props up one portcullis block as part of the locking system
• A satellite pyramid 55 meters south has corridors that resemble a draft of Khufu’s Grand Gallery
• Workers leveled the plateau by flooding a grid of trenches and cutting the bedrock to the water line
• Nicole Alexanian and Felix Arnold describe a 700 meter causeway, a wind-deflecting valley temple, and garden basins as a man-made setting built around an artificial mountain