Tunnel to NowhereStanding on wooden steps that protect a 3,300-year-old stone staircase, Egyptian antiquities chief Zahi Hawass poses in 2009 in a mysterious tunnel that links the ancient tomb of Pharaoh Seti I to ... nothing.

After three years of hauling out rubble and artifacts via a railway-car system (rails visible at left), the excavators have hit a wall, the team announced last week. It seems the ancient workers who created the steep tunnel under Egypt's Valley of the Kings near Luxor (map) abruptly stopped after cutting 572 feet (174 meters) into rock.

Hawass, also a National Geographic Society explorer-in-residence, believes work on the tunnel began during the pharaoh's 15-year reign (1294-1279 B.C.), but after the tomb above it was already complete. Work may have stopped when Seti I died.

Archaeologist Mustafa Waziri, regional director for the Egyptian antiquities council, said: "I think they were planning to make another burial chamber down there. Suddenly they stopped. But the condition of the stairs is amazing."

(The National Geographic Society owns National Geographic News.)

—Andrew Bossone and Ted Chamberlain

Photograph by Amr Abdallah Dalsh, Reuters