The 2,300-year-old royal tomb of a Nubian pharaoh appears nearly untouched--and submerged in rising groundwater. Nastasen's watery tomb is located at the ancient site of Nuri, which sprawls across more than 170 acres of sand near the east bank of the Nile River in northern Sudan. Seen from the sky, its most commanding feature is an arc of some 20 pyramids built between 650 B.C. and 300 B.C. These pyramids mark the burials of Kushite royals, the "black pharaohs" who operated as vassals on the gold-rich southern edges of the Egyptian empire, but who emerged as a force of their own during the political chaos that followed the demise of the New Kingdom.