James Joyce's "Ulysses" — sections of which first began to appear 100 years ago — immerses the reader in the sights, sounds and smells of early 20th-century Dublin. As Stephen Dedalus and Leopold Bloom meander through city streets, their thoughts and experiences are, for the most part, perfectly ordinary. Joyce's prose, however, is anything but. The linguistic gumbo of "Ulysses," a thick mulligan stew containing everything in the kitchen, makes other writing seem like tasteless clear broth.

Let us jump ahead now to our own time. In the loosely linked essays of "The Last London," Welsh writer and filmmaker Iain Sinclair tramps the back streets and canal towpaths of Hackney, closely observing this East London borough where he has lived for most of his adult life. He describes people sleeping rough under bridges, the garb and rituals of city cyclists, artistic graffiti on ancient brick walls, the closing of churches, the rise of upscale apartment buildings, noise from unending street repairs, the proliferation of overtly mendacious signage ("Putting People First"), and the sometimes tense interactions of a white, black, Middle Eastern and Asian population.

All admirably sociological, of course, but you don't read Iain Sinclair just because he's an expert on London's multilayered urban life; what matters, as with Joyce, is his prose, page after page of verbal riffs and astonishments. For example, Sinclair neatly sums up Walter Sickert, the late-19th-century artist, as the painter of "dead-cigar Sunday afternoon ennui after laboured coitus in rented railside properties." During his daily walks, he wryly observes the Regent's Canal towpath crowded with jogging "body-image gladiators" and fit young women who "haul accessorised dogs that are killing themselves to keep up."

Sinclair's many admirers include Alan Moore — graphic novelist extraordinaire — who has called him "Britain's finest writer" and Michael Moorcock, the dean of English fantasy and science fiction, who proclaims his work "the finest contemporary writing we have." Nearly all of Sinclair's books, whether fiction ("White Chappell, Scarlet Tracings" ) or nonfiction ("London Orbital: A Walk Around the M25") mix real history and refracted autobiography. His books, then, are hybrids, like so much of Joyce — and Kafka, W.G. Sebald, Robert Walser and Georges Perec.

Many of these pieces, written between 1975 and 2016, make fun of contemporary smartphone addiction and the "mad heads-down soliloquists" who are "wedded to these digital phylacteries, carried everywhere to announce an irrational faith in dangerously corrupted information systems." Every one of them "pokes and prods, making it seem that the devices are malfunctioning." One East London park, he notes, has now become the "site of elective infantilism: mature adults on psychedelic skateboards bopping to earworm infills."

In a mildly contrarian essay about cycling, Sinclair dismisses the belief that "getting London mounted on two wheels would solve our problems; not only transport chaos, but quality of life. We would be better people in a healthier city. We would be almost Dutch or German or Scandinavian." He points out that because of speeding bicycles, pedestrians can no longer walk easily on shared paths and that well-off yuppies are mainly the ones who pedal, thus avoiding the "stuttering buses, where they would be brought into contact with the sweltering mass of immigrant humanity." He also stresses what every cyclist knows: The only certainties are "theft and road accidents." In the end, Sinclair prefers to travel on foot. "Only when we walk with no agenda does the past return."

In other pieces, this marvelous essayist reflects on the funeral of Margaret Thatcher, that "mummified icon of Britishness," and the appalling rise of the current occupant of the White House: "All this trumpeting inflatable was waiting for was the invention of worldwide social media, slavish followers hungry for the latest jab of his thumb."

Against Donald Trump's "meaningless visibility, his compulsive Tourette's tweeting," Sinclair contrasts the "measured respect for the printed word" demonstrated by the quietly polite, but elusive book scout Martin Stone, whose death he mourns. "The creatures of Trump's court were spooks of antisocial media, dripping poison into the veins of the internet. Martin was that person you can never contact, until he walks into your shop, and out of it into another universe. He was off-grid before there was a grid."

Yet Stone's charisma and the rarities he unearthed made his Camden Passage book stall a Mecca for "top-dollar dealers from Covent Garden, Savile Row and California" as well as for "mildewed weirdo collectors of single titles" and ordinary book-lovers. Whatever your interest, Stone "fulfilled some strange need: the outsider/insider with the keys to the celestial library."

In "The Last London," Sinclair profiles a poet friend of W.G. Sebald, several visual artists and a photographer who snaps pictures of pigeons in their nests under bridges. He makes clear his abhorrence of the "gesture politics" that resulted in Brexit and aptly describes the western world's current social climate as one of "managed despair." Even more acutely, he recognizes that "the defining process of the times is migration," then pauses to wonder if a homeless man on a park bench might actually be "one of the Lamed-Vav Tzadikim, the thirty-six righteous ones of mystical Judaism." If so, that pillar of the earth would have wandered onto the old stomping grounds of strong-arm enforcer Lenny McLean, known as "the hardest man in Britain."

Because of the strongly English focus and the kaleidoscopic richness of its style, this isn't a book you can race through. Instead you'll want to take your time, look around and occasionally listen in on conversations, as you saunter along with Sinclair on these rambles into a strange and vanishing London.

Michael Dirda reviews books every Thursday for The Washington Post.

the last london

True Fictions from an Unreal City

By Iain Sinclair

Oneworld. 336 pp. $28.99