Although not in the geographic center of the District of Columbia, the Capitol is the focus by which the quadrants of the district are divided.
The building is marked by its central dome above a rotunda and two wings, one for each chamber of Congress: the north wing is the Senate chamber and the south wing is the House of Representatives chamber. Above these chambers are galleries where people can watch the Senate and House of Representatives.
The Capitol is an example of Neoclassical architecture with influences from ancient Greece and Rome.
The site for the United States Capitol chosen by Pierre Charles L'Enfant was Jenkins Hill, which rose 88 feet above the Potomac River.
All rooms in the Capitol are designated as either S (for Senate) or H (for House), depending on whether they are north (Senate) or south (House) of the Rotunda.
Up to four U.S. flags can be seen flying over the Capitol. Two flagpoles are at the base of the dome on the East and West front. These flagpoles have flown the flag day and night since World War I. The other two flagpoles are above the North and South wings of the building and fly only when the chamber below is in session.
Under the Rotunda there is an area known as the Crypt. It was designed to look down on the final resting place of George Washington in the tomb below. At the request of his wife, Martha, however, Washington was buried at Mount Vernon, and as such the area remains open to visitors. The Crypt now houses exhibits on the history of the Capitol.