The United States Capitol building as it sits atop Capitol Hill on the eastern side of the National Mall in Washington, D.C. The building, which is the meeting place of the United States Congress, began construction on September 18, 1793. The Capitol building is composted of a central domed housing a rotunda, a north Senate wing, and a south House of Representatives ring. On December 2, 2008, a Capitol Visitor Center was opened which allows tourists a glimpse inside the building.