OUTSKIRTS OF BAGHDAD, Iraq - The road led to what looked like a carport - a really long one, but a carport nonetheless. At the rear, though, was something far more interesting to U.S. forces.
A door. And behind it, lined with moss, a cave entrance - another mysterious, potentially dangerous gateway into the murky world of Baghdad underground.
Was this a path to one of Saddam Hussein's notorious hideouts? Were booby traps - or, worse, Iraqi soldiers lurking inside?
"We wanted to know if there was enemy in there. We thought there was enemy in there," said Lt. Col. Lee Fetterman, commander of the 101st Airborne's 3rd Battalion, 3rd Brigade.
Years of rumors about tunnels Hussein had built raised the possibility that just about anything could be underground - troops, weapons of mass destruction, the Iraqi leader himself.
A former Iraqi scientist who fled during the 1991 Gulf War, Hussein al-Shahristani, told CBS' 60 Minutes in February that there were "more than 100 kilometers (about 60 miles) of very complex network, multilayer tunnels."
So far, a series of tunnels under Baghdad's international airport have been discovered. On Monday, U.S. forces captured an Iraqi colonel in one tunnel who was calling in artillery fire from his hideout, said Lt. Mark Kitchens, a spokesman for the U.S. Central Command.
When the American forces got to the carport, they initially believed it to be one of the intricate tunnel systems that dot the Iraqi capital.
Carefully, about 150 U.S. soldiers headed out to explore it, first donning the night-vision goggles.
They went through shin-deep mud and down a set of dark stairs. Then they went in the door.
Inside, they found 12 rooms, each with white marble tile floors, 10-foot ceilings and fluorescent lighting.
In some rooms they found office furniture.
They also found bathrooms, showers, and at least one area littered with cigarette butts, tea bags and other indications that the area was abandoned not too long ago.
But no one was there. They found only opulence - far different from the Spartan Iraqi military quarters they have passed through recently.
So they emerged from their first foray knowing at least one thing: This was no enlisted man's hideaway.
For now, at least, the rest remains a mystery - including the task of making certain the tunnels aren't connected to any others.