for National Geographic News
The pyramid is thought to house the tomb of King Menkauhor, who is believed to have ruled in Egypt's 5th dynasty for eight years in the mid-2400s B.C.
Long since reduced to its foundations, the structure was previously known as Number 29 or the "Headless Pyramid." It was mentioned in the mid-19th century by German archaeologist Karl Richard Lepsius.
Then it disappeared in the sands of Saqqara, a sprawling royal burial complex near current-day Cairo.
It took Egyptian archaeologists about a year and a half just to remove all the sand above the pyramid.
"After Lepsius the location of the pyramid was lost and the substructure of [the] pyramid never known," said Zahi Hawass, secretary general of Egypt's Supreme Council of Antiquities.
"It was forgotten by people until we began to search this area and a hill of sand, maybe 25 feet [7.6 meters] high."
Hawass is a National Geographic explorer-in-residence. (The National Geographic Society owns National Geographic News.)
Old Kingdom Clues
Nothing on the pyramid specifically names its owner, and the majority of the structure has been destroyed, so Egyptian archaeologists had to put several clues together to identify it.
Past archaeologists have disputed the date of the pyramid, usually putting it in either the Old Kingdom, between 2575 and 2150 B.C., or the Middle Kingdom, between 1975 and 1640 B.C.
But the recent research determined that the pyramid lacked the winding mazes typical of a Middle Kingdom temple.
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