The Giant Hat of the Capitol!

This amazing dome sits right on top of the United States Capitol building in Washington, D.C. It's like the cherry on top of a very important cake! The dome is so big that it's the center point for maps of the whole city. If you look at a map of Washington, D.C., the Capitol dome is right in the middle, like a giant compass pointing north, south, east, and west!

You might think it's made of stone, just like the rest of the building, but surprise! It's actually made of metal, like a giant tin can! It's called cast iron, and it's painted to look like stone. It's like wearing a costume! This metal hat is super heavy, weighing as much as 4,550 school buses! That's a lot of buses!

This isn't just one big metal hat; it's actually two hats stacked on top of each other, one inside the other! It's like having a hat inside another hat. This clever design helps make the dome super strong. At the very tippy-top, there's a shiny statue called the Statue of Freedom, watching over the city.

A very smart person named Thomas U. Walter designed this incredible dome. It took a long, long time to build, from 1855 to 1866. That's longer than you've been alive! It cost a lot of money, too, more than a million dollars back then, which is like millions and millions of dollars today. It was built by a company that made things out of iron.