The centerpiece of the Southwest Washington Redevelopment Area was to be the 10th Street Mall / L'Enfant Plaza, a two-block thoroughfare extending from Independence Avenue south. As its name and symbols suggest, the complex's planners aspired to the standards and architectural excellence set by the city's first planner. Bridging the railroad tracks and the Southwest Expressway, this complex was to become a commercial and cultural hub of the city, as well as the entrance to the new Southwest. Office buildings, a hotel, a shopping center, restaurants, and a cultural center were to be located along the 10th Street spine and on the eastern cross axis. The cultural center ultimately was located instead in Foggy Bottom as the John F. Kennedy Center for the Performing Arts. The shopping arcade adjacent to the plaza serves nearby office workers and bustles on weekdays but is otherwise moribund. The hotel atop the shopping center is isolated from other downtown hostelries.
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. Cassutta, 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.