When completed in 1975, the Citicorp building (as it was then named) garnered initial attention for its silvery aluminum-clad tower, poised for takeoff on four 10-story stilts and topped with a rakish slanted roof. But its interior design quickly gained an independent reputation among members of the public and public space specialists. Although the building exhibited four different kinds of privately owned public space — a plaza, open air concourse, through block arcade, and covered pedestrian space — it was the covered pedestrian space and its seven-story atrium that became the featured attraction.

The development occupies almost the entire block bounded by Lexington and Third Avenues, and East 53rd and 54th Streets, excluding a small area at the corner of East 53rd Street and Third Avenue. In its middle is the 7,247-square-foot covered pedestrian space, on the building’s concourse level below the street. There are six access points from the surrounding streets, including two entrances to the through block arcade and down the escalator from either East 53rd or 54th Streets between Third and Lexington Avenues, another entrance on East 53rd Street closer to Lexington Avenue, an entrance from the plaza down steps into and through the open air concourse from the northeast corner of East 53rd Street and Lexington Avenue, an entrance from the Lexington Avenue plaza closer to East 54th Street through exterior and interior corridors and down an escalator, and an entrance down steps from the southwest corner of East 54th Street and Third Avenue and through a private restaurant. This last path is confusing, even treacherous, as users must navigate past waiters, patrons, and crowded tables along a trail that is not always expressly delineated. Still, compared with most indoor spaces containing below-ground levels, this one is unusually accessible from the street, and such permeability is an important element in enticing pedestrians to visit otherwise off-the-path, below-ground interiors.

Once there, the full scope of the cavernous atrium is revealed, rising seven stories and cresting in three glass A-frame skylights. The covered pedestrian space level is ringed by circulation corridors and storefronts at concourse and street levels, while the upper levels consist of glass picture windows interspersed with bands of polished aluminum. Public space users from below watch the office tenants above as much or more than the office occupants peer down.

The space features a cornucopia of usable amenities. Numerous movable round and square tables and chairs are packed onto the polished granite floor. The kiosk and surrounding stores furnish food for a crowd that, especially at lunchtime, can be so large that people sometimes must wait for tables and chairs. Thankfully, even at noon when crowds begin to gather, the space is never too noisy or chaotic. Its size absorbs sound, while its muted lighting scheme and natural sunlight intermittently filtering through the skylight calm the visual scene. The recent addition of muzak will hopefully be short-lived. The requirement that there be one use or sales area for every 25 feet of frontage on the East 53rd Street side of the space is meant to encourage a diversity of casual restaurants and takeout facilities that, in the past, has worked so well here. The women’s restroom is located underneath the East 54th Street through block arcade entry; the men’s under the East 53rd Street entry.

Since its opening 25 years ago, this covered pedestrian space has displayed a mix of identities molded by private and public aspirations. For a time, it sought status as a shopping mall, advertising itself through snazzy marketing plaques as the “Market in the Atrium,” where “The Sky’s the Limit. Boogie Woogie. Rock ‘n Roll. And All that Jazz. Little Bit of Broadway. And Lots of Razzmatazz. It’s Magical. A Festival. A Carnival. Day and Night. A Pure Delight. Come on in the Atrium. For Fun. For Free. The Place to Be.” Market realities and strategic repositioning eventually altered this approach, replacing it with more modest retail goals.

In the late 1980s and early 1990s, the space was heavily used on weekends by immigrants from Hungary, Czechoslovakia (when it still was Czechoslovakia), and other Eastern European countries. They would come in weekly from Forest Hills and other city neighborhoods for a rendezvous and snack with friends. That Citicorp, the quintessential representative of capitalism, should provide space for a reconstituted community of Iron Curtain country refugees, was an amusement commented upon by several of the regulars. The space to this day serves as venue for special occasions. One group of cousins arranges a yearly get-together, as their spokesperson describes, “We come from Brooklyn. This is a great meeting place. We have the restaurants here, and we have a favorite . . . and then [we] come back here and have our dessert and coffee and talk a little longer, and we show pictures of our children, wedding pictures, children, and whatever. I like seeing people of all ages too. I like to study them. There are all kinds that make up the world, and you can see some that are very lonely, others studying.” The space appears to be best understood as a hybrid, neither fully dedicated to retail, like Trump Tower, nor fully devoid of retail, like 590 Madison Avenue. It gains much of its identity from its diverse, changing set of users, like neighborhoods throughout the city.

The covered pedestrian space is one of two indoor spaces here. Entered down several steps from the public sidewalk, the through block arcade bisects the building, east and one level above the covered pedestrian space floor, connecting East 53rd and 54th Streets. The level change from the sidewalk tends to hide the through block arcade from sidewalk pedestrians, discouraging pedestrians from using a shortcut that requires marching down and up steps. The two outdoor spaces are best understood from a standing start at the northeast corner of Lexington Avenue and East 53rd Street. At street level is the plaza, a small sliver of extra sidewalk along the avenue that features a well-utilized seating ledge and three flagpoles. It would be interesting for flagpoles, a common obstruction in public spaces, to fly specially designed public space flags along with more traditional ones. The plaza sliver closest to East 54th Street fronts the geometrically challenging St. Peter’s Church, known for its jazz vespers, organ recitals, and Louise Nevelson sculptures. A window on East 54th Street allows the pedestrian to watch the congregation.

Like 55 Water Street with its elevated plaza, Citigroup Center is one of a small group of catalyst buildings whose proposed development literally inspired the legal introduction of a new category of bonused public space, the open air concourse, to the Zoning Resolution. The two-level sunken open air concourse is entered down 24 steps from the corner of Lexington Avenue and East 53rd Street. Water cascades along the face of a primitive, monolithic structure next to the steps, reaching its aural crescendo at the bottom. Softened by several trees growing out of the pavement, the upper level of the open air concourse is dedicated to circulation into the building interior and the covered pedestrian space to the east and into the subway station to the southeast. A lower level, north and down another eight steps, supplies metal tables and seats. The views from here are stimulating. Above and east is the underbelly of the cantilevered tower, whose awesome mass and engineering convey the feeling one might have at the base of a rocket. Another view of the church interior is available to the north.