The Sony Building is no longer the Sony Building, but most New Yorkers still call it that, and the lobby is now a public garden one can walk into off the street.

The building is at 550 Madison, between 55th and 56th. Philip Johnson designed it in 1984 — the famous postmodern tower with the Chippendale crown that critics quarrelled over for two decades, and that most of us long ago accepted as part of the skyline. Sony owned it until 2016. Olayan bought it. They hired Snøhetta to renovate it, and Snøhetta did the thing where the architect promises to enlarge the public space rather than reduce it, and one does not quite believe them, until one walks in.

The public garden takes up most of the ground floor now. There is a seventy-foot glass roof. The seating is a mix of long shared tables, lounge chairs, and architectural concrete steps that double as benches. Plants — real ones, in real soil, growing toward the light.

On a first visit one assumes the eviction is coming within twenty minutes. It does not come. Office workers from the floors above descend at lunch with food from home. A man in an expensive coat conducts a phone call for ninety uninterrupted minutes. A tour group passes through. A woman reads a novel and falls asleep.

This is a POPS — a privately owned public space. There are roughly five hundred and fifty of them in New York. Developers were required to make them publicly accessible in exchange for building taller than zoning would otherwise allow. Most are bad: paved plazas with three trees, intended for nobody. A few are extraordinary. The 550 Madison garden is one of the few.

The thing to internalize is that one has a legal right to be there. The owner is required, by the 1981 bargain the developer struck with the city, to admit you during business hours and let you sit. No purchase. No explanation. One may take phone calls. One may read. One may sleep.

There is a coffee shop inside, but one is not obligated to use it. There are bathrooms — at the back, past the elevator banks — that are public. The garden stays open until ten on weekdays.

Your correspondent uses the garden for phone calls, for meetings that could not justify a coffee shop, and for the twenty minutes of quiet sometimes required before the next obligation. It is, more than anything, the most useful interior between Park and Fifth, between the Forties and the Sixties.

The most New York thing about the building is that almost none of the fourteen thousand office workers in the tower above know the garden exists. They pass it every day on their way to the elevators. The garden, it turns out, is for someone else. For us.