Dashur

Sneferu's unusual Bent Pyramid

Friday 21 December: A handful of miles south of Saqqara is the bleak desert landscape of Dashur where two later, Old Kingdom, stone-built pyramids still survive, both constructed by 4th Dynasty pharaoh, Sneferu, around 4,600 years ago.
Bent Pyramid
Sneferu's architects built the bottom-half of this smooth limestone-clad structure at the same steep angle as Zoser's earlier step pyramid. But following the collapse of a similar pyramid at Meidum they were forced to complete the top-half at a reduced building angle, thus producing the misshapen 'Bent Pyramid'.
Red Pyramid
Lessons learnt, Sneferu's builders started again and constructed the whole of the Red Pyramid at the same shallow angle as the top-half of the Bent Pyramid. Perfectly symmetrical and a joy to admire the Red Pyramid remains the world's oldest true pyramid. The fine-quality limestone cladding was removed in antiquity exposing the red masonry beneath that gives the Red Pyramid its name. The steep entrance tunnel leads down through two anti-chambers to the amazing high corbelled-ceiling of the burial chamber where, it's thought, Sneferu was interred. It seems hardly surprising that he would have chosen to be entombed here rather than within the uglier double-sloped Bent Pyramid nearby. 
Slideshow of Dashur.