The Red Pyramid, (North Pyramid), at the Dahshur necropolis in Cairo, Egypt.

The Red Pyramid, (North Pyramid), is the largest of the three major pyramids located at the Dahshur necropolis in Cairo, Egypt. Named for the rusty reddish hue of its red limestone stones, it is also the third largest Egyptian pyramid, after those of Khufu and Khafra at Giza. It is also believed to be Egypt's first successful attempt at constructing a 'true' smooth-sided pyramid. The Red Pyramid was the third pyramid built by Old Kingdom Pharaoh Sneferu, the founding monarch of the 4th dynasty during the Old Kingdom. suggesting a reign from around 2613 BC to 2589 BC. (Photo by: Universal History Archive/Universal Images Group via Getty Images)