Photograph of people walking outside on a Self-Guided Tour of Capitol Hill
Visitors can tour many highlights on Capitol Hill without registering.


The Architect of the Capitol’s challenge is unique – maintaining aging, iconic buildings; adapting state-of-the-art technology; and increasing responsiveness to environmental, security and safety considerations in a rich historical setting.
The Architect of the Capitol's challenge is unique – maintaining aging, iconic...


Federal Office Building No. 8, now known as the O’Neill House Office Building, under original construction. Photo courtesy of the FDA.
A brief history of the O'Neill Building.




The large circular area on the first floor of the U.S. Capitol Building is called the Crypt. The 40 Doric columns of brown stone surmounted by groined sandstone arches support the floor of the Rotunda

This center section of the building was completed in 1827 under the direction of the third Architect of the Capitol, Charles Bulfinch. The star in the center of the floor denotes the point from which the streets in Washington are laid out and numbered. Located in the Crypt are 13 statues from the National Statuary Hall Collection, representing the 13 original colonies, and the Magna Carta replica and display.

Find out how the Crypt got its name.

Last Updated: December 15, 2015