Critics call it the "Pig Dig," a massive construction project they say is pigging out on federal tax dollars right in Congress' back yard.
The Capitol Visitor Center, now 85 percent complete, will be three stories, with state-of-the-art theaters, a great hall, even a 450-seat auditorium.
The goal of the center? Tighter security and an improved learning experience for millions of tourists. The problem, critics say: It's wildly over budget and years behind schedule.
"We've created this Taj Mahal on the Capitol grounds!" says Steve Ellis with Taxpayers for Common Sense. "[It's] a boondoggle."
In 1995, it was projected to cost $100 million and be ready in 1999. But the digging didn't begin until 2002. By then, the cost had ballooned to $265 million, and kept growing and growing and growing. The latest estimate is nearly $600 million, and the visitors center won't be ready until late 2007, at the earliest.
Just last week some members of Congress gave the project their Golden Drain award. The qualifications?
"Pitiful oversight, exploding costs and embarrassing results," says Rep. David Obey, D-Wis.
Critics say there's little question who's at fault. "I think Congress should get the lion's share of the blame," says Ellis.
Ellis says Congress has tacked on hundreds of increases in spending, from new office space to security upgrades, to yet another tunnel for emergency escapes.
Defenders of the project often point to the Capitol itself. When the dome was built in the 1860s, the final price tag was $1 million — ten times the original estimate. There was a flood of criticism then, too, but it all stopped when they saw the final product.
So might the criticism here end after it's complete? Depends on whom you ask.
"It is the Capitol building, a national monument, so in that respect it's worth it," says one D.C. visitor.
"A half billion, for what?" asks another.
For a project that some say spiraled out of control — right under Congress' nose.