Red Pyramid — Wikipedia

The Red Pyramid, also called the North Pyramid, is the largest of the pyramids located at the Dahshur necropolis in Cairo, Egypt. It is the third largest Egyptian pyramid, after those of Khufu and Khafre at Giza. It is believed to be Egypt's first successful attempt at constructing a "true" smooth-sided pyramid. The pyramid is named for the rusty reddish hue of its limestone, but it was not originally red – it was clad in white Tura limestone. During the Middle Ages, much of the cladding was taken for buildings in Cairo, exposing the red limestone. Only a few white blocks remain, at the...