‘Manhattan’s Little Secrets,’ a book that knows everything about the borough

John Tauranac’s latest book delves into the often-overlooked.

Maybe you think you’re a savant of New York City trivia. Good as you are, wait until you meet John Tauranac.

Tauranac has observed and mapped New York for decades. He worked on the creation of NYC’s famous subway map in the 1970s, and has since written multiple city guidebooks. But in his new book, he focuses just on little unnoticed objects and hidden sites all around Manhattan — the secrets of the borough that you can only know when you’ve walked every block, like he says he has.

Here are five particularly interesting selections included in “Manhattan’s Little Secrets,” on sale Wednesday. Enjoy them, because this knowledge doesn’t grow on trees. Even Tauranac knows his limits, and says he won’t be doing follow-ups for other boroughs about which he is less familiar.

“Thomas Wolfe was right,” he said in an interview, “only the dead know Brooklyn.”

The Knickerbocker door, east end of Platform One at Times Square, on the 42nd Street Shuttle

“If you had walked through this door marked ‘Knickerbocker’ in 1906, you would have entered a fantasy world,” writes Tauranac.

The old portal once led directly from the subway to the swanky Hotel Knickerbocker, featuring a Grill Room decked out in Elizabethan style and a fountain in the lobby.

The door may have been allowed because the subway tracks actually trespassed onto hotel property. Technically, you could go through the hotel basement and not pay, though Tauranac notes that “the odds of this door having ever actually been open onto the platform are pretty slim.”

Second life for a lost work of art, in the Public Hotel, 215 Chrystie Street

It’s one of the great New York stories: during the Great Depression, the uber-wealthy Rockefeller family commissioned Mexican muralist Diego Rivera to paint a landmark fresco for Rockefeller Center. Rivera’s answer railed against the sins of capitalism, in a gigantic work of art that featured a portrait of Lenin and peaceful demonstrators whose sign read “We Are Hungry. We Want Bread.”

The Rockefellers weren’t thrilled about all this and ultimately ended up destroying the mural.

But it lives on, in a way: as a giant tapestry copy in the Public Hotel’s Diego Room. “At seven by eighteen feet, the tapestry is about half the size of the original,” writes Tauranac, “but it will no doubt come to loom as large as the original looms in legend.”

Better than Big Ben at the Metropolitan Life Tower, Madison Avenue and 24th Street

People go to London just to experience Big Ben’s chimes, but our own nearly-as-magnificent public clock mounted on the Metropolitan Life Tower doesn’t even make Top 10 lists.

When it was built in the early 20th century, it was the tallest building in the city at 700 feet. Its clock tower is planted twice as high as the one in London, notes Tauranac.

Our bells may be smaller but when they were still in use, the sounds could be heard as far away as New Jersey.

A non-public piece of sidewalk, 110 Seventh Avenue South, at the southwest corner of Christopher Street

Thanks to the condemnation of a swath of Greenwich Village in the 1910s to build the subway, one landowner lost his plot — except for a minuscule sliver of land shaped like a triangle on what became sidewalk. The estate that still technically owned the tiny few-foot plot refused to sell it to the city, and instead installed a mosaic: “Property of the Hess estate which has never been dedicated for public purposes.”

And the award for most New York: a sculpture within the central portal of the Cathedral of St. John the Divine, Amsterdam Avenue and 112th Street

In the mode of great medieval churches this monumental cathedral is still somewhat unfinished, though its cornerstone was laid in 1892. One great piece of recent construction is a carving near the central portal that shows a collapsing Brooklyn Bridge, a ruined stock exchange-like building and a bunch of skeletons, notes Tauranac. Work on the carving started in the 1980s when lots of city infrastructure seemed insecure — in 1986, engineers discovered that aspects of the Manhattan Bridge were rusty to the point of near-collapse. So maybe the apocalypse was on the mind of the sculptors. In the modern era, we’d call them subway riders.

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