Some writers are bound to a single desk, a single window, a single view of a single tree. Susan Sontag was not one of them. To make a pilgrimage to the New York of Susan Sontag is to walk a map of restlessness — a life lived in apartments stacked with books, in rooms chosen less for comfort than for the volume of shelving they could hold, in a city she treated as both subject and study. She was the most public American intellectual of her generation and one of its most private writers, and the addresses where she actually put words on paper tell you something the essays do not: that thought, for her, was a physical labor, harnessed to flesh and to floor plans.

This is a walking pilgrimage through the Manhattan where Sontag lived and wrote — what is verifiable, what is still standing, and what it felt like to be in the orbit of a mind that never stopped working.

The penthouse above Chelsea: 470 West 24th Street

If there is one address that belongs to Sontag the way a study belongs to a scholar, it is the top-floor penthouse at 470 West 24th Street, in the West Chelsea complex called London Terrace. She owned the twentieth-floor penthouse there — a roughly 2,700-square-foot apartment that, after her death in December 2004, was sold by her estate in 2006 for $3.95 million, and which later passed through several owners, including, in 2013, Sopranos creator David Chase, who paid $9.65 million for it. The real-estate record is unusually well documented, which is fitting: this was the home of the last quarter-century of her life, the place that held her library.

And the library is the point. Sontag’s personal collection ran to roughly fifteen thousand books, and the penthouse was organized around them — described by those who visited as a sparsely furnished set of rooms whose true furniture was the shelving, the spines, the stacks. She did not collect books as objects to be admired behind glass; she read them, annotated them, argued with them. To stand on West 24th Street and look up at the building’s brick-and-terra-cotta crown is to understand the architecture of her working method. The essays that feel so weightless on the page — the famous turns in Against Interpretation, the cool moral pressure of Regarding the Pain of Others — were assembled in a room that was, quite literally, built out of other people’s sentences.

The building itself deserves the pilgrim’s attention. London Terrace occupies a full city block in Chelsea, between West 23rd and West 24th Streets and Ninth and Tenth Avenues. It was completed in 1930–1931 by the developer Henry Mandel and designed by the architectural firm of Farrar & Watmough as a unified composition — fourteen contiguous buildings of seventeen to nineteen stories, their facades enlivened with North Italian Romanesque, Gothic, and Renaissance motifs. When the complex opened, it transformed the block, and nearly a century later it remains one of the great pre-war apartment fortresses in Manhattan. Sontag’s was the building on the West 24th Street side; her windows looked out over the rooftops of Chelsea toward the Hudson.

Pilgrim notes. 470 West 24th Street sits between Ninth and Tenth Avenues. It is a private residential building — there is nothing to enter, and residents’ privacy should be respected entirely. The pilgrimage here is a sidewalk pilgrimage: stand across the street, look up at the penthouse line, and consider the fifteen thousand books that once sat behind those high windows. The nearest subway is the C/E at 23rd Street and Eighth Avenue, a short walk east. The block is quiet, low-traffic, and best visited in late afternoon when the western light catches the terra-cotta.

The Upper West Side years: 340 Riverside Drive

Before Chelsea, there was the Upper West Side. In the 1970s, Sontag lived at 340 Riverside Drive — an apartment that figures in the memoirs of those closest to her. The novelist Sigrid Nunez, who lived in the apartment with Sontag and Sontag’s son, David Rieff, in the years around 1976 to 1978, later wrote about that household in her memoir Sempre Susan, and the portrait that emerges is of a domestic life organized entirely around intellectual production: late nights, constant reading, conversation as a kind of competitive sport.

This was a crucial stretch of Sontag’s writing life. On Photography — the book that arguably did more than any other to install her as the defining critic of how images shape consciousness — was published in 1977, in the midst of these Riverside Drive years. It is impossible to walk past 340 Riverside without thinking of the famous opening move of that book, the idea that to photograph is to appropriate the thing photographed, to place oneself in a certain relation to the world that feels like knowledge but is really acquisition. That argument was worked out in an apartment overlooking the Hudson, a few blocks from Riverside Park, in a building that still stands today.

Pilgrim notes. 340 Riverside Drive is on the Upper West Side, near West 106th Street (Duke Ellington Boulevard). Like the Chelsea penthouse, it is a private residence and should be viewed only from the public sidewalk. Pair the visit with Riverside Park directly across the drive — the benches along the upper promenade offer the same river view Sontag would have had — and with a walk to the nearby stretch of Broadway, where the bookstores and cafés of the old intellectual Upper West Side once clustered. The 1 train at 103rd or 110th Street is the closest transit.

The mind harnessed to the city

Sontag’s journals make plain how inseparable her thinking was from her physical situation. The second volume of those journals, published posthumously and edited by David Rieff, takes its title — As Consciousness Is Harnessed to Flesh — from an entry she made in May 1965, when she was thirty-two. Sketching an idea for a novel about an artist thinking about his work, she wrote in the margin of the entry: “A spiritual project — but tied to making an object (as consciousness is harnessed to flesh).” It is as good a description of her own method as any she ever produced. The thought is spiritual; the work is an object; the two are bound together. And the binding happened in rooms — in apartments, at desks, surrounded by the physical fact of fifteen thousand books.

That volume of journals tracks her exact arc through the city’s intellectual world: from a fledgling participant in the artistic life of New York in the early 1960s to a world-renowned critic by the time Against Interpretation appeared in 1966. The New York she moved through in those years — the downtown lofts, the uptown apartments, the magazine offices, the screening rooms — was the laboratory in which she became “Susan Sontag,” the name that would eventually function less like a person than like a position one took.

Building your own Sontag walk

A Sontag pilgrimage is not a tour of preserved interiors; both of her major apartments remain private homes, and there is no plaque, no gift shop, no rope line. This is, if anything, more appropriate to her. Sontag distrusted the sentimental and the merely commemorative. The right way to honor her is to do what she did: read, and then walk, and then read again.

A coherent day might begin in Chelsea, at the foot of London Terrace on West 24th Street, with a copy of Against Interpretation in your bag. From there, the pilgrim can walk south and east into the Chelsea gallery district — the world of images that Sontag spent a career interrogating — before heading uptown to 340 Riverside Drive and Riverside Park, where On Photography was written, to sit on a bench above the Hudson and read the opening pages with the same river in view that she had. The two addresses, taken together, span the productive middle and late decades of her life and trace the geographic logic of an intellectual who treated the whole of Manhattan as her reading room.

For the dedicated, the pilgrimage extends naturally to the institutions that now hold her: research libraries and archives have acquired Sontag materials, and the journals and books remain in print and in circulation. But the essential pilgrimage is the simplest one. Stand on the sidewalk. Look up at the windows. Remember that behind glass like that, a consciousness was once harnessed to flesh, to a desk, to a city, and to fifteen thousand books — and that the result is still on the shelf, waiting to be argued with.

If you go

470 West 24th Street (London Terrace), Chelsea — Sontag’s penthouse, where she lived and worked in the last decades of her life. Private building; view from the sidewalk only. Nearest transit: C/E at 23rd Street & Eighth Avenue. Best paired with the Chelsea galleries and the High Line a few blocks west.

340 Riverside Drive, Upper West Side — Sontag’s home during the 1970s, including the years around the publication of On Photography (1977). Private building; view from the sidewalk only. Nearest transit: 1 train at 103rd or 110th Street. Best paired with Riverside Park directly across the drive.

Read before you walk: Against Interpretation (1966), On Photography (1977), Regarding the Pain of Others (2003), and the journals As Consciousness Is Harnessed to Flesh: Journals and Notebooks, 1964–1980 (edited by David Rieff).