United States Capitol Crypt, Circular chamber beneath the United States Capitol Rotunda in Washington DC, United States.

The United States Capitol Crypt is a large circular chamber directly beneath the Rotunda, ringed by forty neoclassical Doric columns of Aquia Creek sandstone whose square capitals support the floor above. A marble compass is set into the tiled floor at the center, and arched openings and recessed panels break the curving wall. It serves as the ground-floor thoroughfare of the Capitol and holds thirteen statues of the National Statuary Hall Collection.

Construction of this room finished in 1827 under Charles Bulfinch's direction, though it was originally planned as an entrance to George Washington's tomb. Those plans were later abandoned, and the space took on a different purpose.

The room's name survives from its intended role as the entrance to a tomb for George Washington, a plan dropped after his death at Mount Vernon. Thirteen statues from the National Statuary Hall Collection stand here, one for each of the original states, among them Anne Whitney's marble Samuel Adams of 1876 and Bryant Baker's Caesar Rodney of 1934. A gold case that held a copy of Magna Carta during the 1976 Bicentennial loan is also kept in the chamber.

The crypt is the main thoroughfare of the Capitol's ground floor and a stop on every tour run through the Capitol Visitor Center. The room lies directly beneath the Rotunda, with the marble compass at its centre; the gift shop sits on the east side and the Congressional Special Services Office in the northwest corner. The chamber below, once reserved for Washington's coffin, later stored the Lincoln catafalque, now kept in the Visitor Center.

A white marble compass stone marks the spot where Washington D.C.'s four quadrants meet, marking the city's geographic center. This often-overlooked stone is a subtle but important symbol of the city's planned design.