Thousands of people tour the US Capitol every year. Very few get a first-hand look inside the building's most iconic feature. There is a secret staircase hidden in the Capitol dome, and it goes ...

Thousands of people tour the US Capitol every year. Very few get a first-hand look inside the building's most iconic feature. There is a secret staircase hidden in the Capitol dome, and it goes ...

Arguably the most magnificent building in Washington, the U.S. Capitol is where visitors go to witness politics in action. Inside ... mention an iconic cast-iron dome added to the structure ...

The U.S. Capitol dome is really an illusion ... The ribs support the thin, outer shell, but the smaller dome inside can support itself. You won't need as much steel with this double-dome design ...