Developer William Zeckendorf of Webb and Knapp and his staff architect I. M. Pei developed the master plan for the site. While the main axis of 10th Street can be viewed as the link between the new Southwest and the rest of the city, L'Enfant Plaza is the heart of the complex, the vital organ pumping activity into the area. L'Enfant Plaza consists of twin office towers, executed by Araldo A. Cossutta, on either side of the plaza, from which stairs descend to the underground parking arcade. Architect Vlastimil Koubek of Washington undertook the design of the hotel, which encloses the east side of the complex. The plaza itself merges into the 10th Street Mall, a band of pink concrete and red granite. The Mall terminates in the south at Banneker Circle, named in honor of Benjamin Banneker, the black mathematician who assisted with the first survey of the District of Columbia. Landscape architect Dan Kiley designed this oval area that serves both as an overlook and the centerpiece of the thoroughfares connecting the mall with the street system to the south.
While nearby office workers quickly utilized the plaza for their dining and shopping needs, the area remained empty during other hours. (Some critics commented that L’Enfant Plaza’s inactivity was a result of the construction of the Forrestal Building, which cut the plaza off from the National Mall). This issue served as illustration of the failures of urban renewal in the city, whereby distinct commercial and residential zones failed to produce a vibrant urban experience. This trend began to change in 2019 with the opening of the immensely popular International Spy Museum within the promenade area of the complex.