Why is the Flatiron Building shaped like a wedge?

A wedge born of a diagonal

Manhattan's street grid is a tidy grid of rectangles everywhere except where Broadway runs through it. Broadway predates the grid and ignores it, cutting diagonally across the island, and wherever it crosses a numbered avenue it leaves behind two odd shapes: a thin triangle and a small square. For more on how the grid works and why Broadway breaks it, see The Grid.

At 23rd Street, Broadway crosses Fifth Avenue, and the triangle left behind became a building site. The square left on the opposite side became a park. That single intersection explains both the Flatiron Building and Madison Square across the street from it, two results of the same collision of street patterns.

The building that rose on the triangle had no choice but to take its shape: narrow and pointed at one end, wide at the other, with two long walls running away from a sharp prow. It is that geometry, not any later design choice, that gives the Flatiron Building its name and its silhouette.

Building the Flatiron

The Flatiron Building opened on October 1, 1902, twenty-two stories and 307 feet tall. It was built as the headquarters of the Fuller Company, a construction firm, and was originally named the Fuller Building after it. Only later did New Yorkers rename it for its resemblance to a cast-iron clothes iron.

The Chicago architect Daniel Burnham designed it with Frederick P. Dinkelberg, treating the tower as a vertical Renaissance palace with Beaux-Arts detail: a three-story limestone base, a long shaft faced in glazed terracotta, and an ornate cornice at the top. The steel frame was engineered by Purdy and Henderson.

That frame was built to withstand four times the strongest wind the site was expected to see, a margin meant to settle doubts about a building this tall and this narrow. The building became a New York City landmark in 1966 and a National Historic Landmark in 1989.

Burnham's Folly and a city expression

Few New Yorkers believed the Flatiron would stand when it went up. They called it Burnham's Folly, convinced that a building so thin at its point could not survive the wind that funnels around Manhattan street corners. The wind at the tip was strong enough that it was said to lift women's skirts and scatter loose banknotes.

According to some accounts, that wind gave rise to the old slang expression twenty-three skidoo, supposedly coined by police moving along gawkers at the building's point on 23rd Street. The phrase's origin is disputed, and no single account of it can be taken as certain, but it has stuck to the building's history regardless.

More than a century later, the building is still standing, and the wind still moves around its prow. Visitors who linger near the plaza on a blustery day can feel the effect the old stories describe, even if the exact origin of the slang cannot be pinned down with confidence.

What you actually see

The best view of the Flatiron Building is from the north, at the pedestrian plaza where Broadway and Fifth Avenue meet at 23rd Street. From there the prow faces the viewer head-on, and the two long walls recede at a sharp angle, so the building appears almost as thin as a single wall rather than a solid structure.

Walk around to 22nd Street at the back and the building reveals its true width, 87 feet across. Looking up anywhere along the facade shows the ornament: bands of terracotta, rows of windows set close enough to read as a woven pattern, and the heavy cornice crowning the roofline.

At street level near the tip sits a one-story extension known as the cowcatcher, added during construction as a shop. The building has been under renovation since 2019, and its owners announced a conversion to residential condominiums in October 2023. Expect scaffolding on parts of the facade, and the interior is not open to visitors.

Madison Square across the street

Madison Square Park, a little over six acres, opened as a public park on May 10, 1847, on land set aside in 1807 as a parade ground and arsenal far north of the city of that era. As Manhattan grew around it, the square became a fashionable address of brownstones and mansions, where Theodore Roosevelt and Edith Wharton were both born.

The park's history holds a few surprises. From 1876 to 1882, the torch-bearing arm of the Statue of Liberty stood here to raise money for the statue's pedestal, long before the completed statue took its place in the harbor; see The Statue of Liberty and Ellis Island for how to visit it today. The first two arenas called Madison Square Garden once stood at the park's northeast corner, and the name traveled uptown with the arena when it moved, so the current Garden is nowhere near this park.

Monuments line the park's edges. At the north end stands the Farragut Memorial of 1881, a bronze by Augustus Saint-Gaudens on a base by Stanford White, honoring the Civil War admiral. An obelisk from 1857 on an island west of the park marks the tomb of General William Jenkins Worth, for whom Fort Worth, Texas is named, and the Eternal Light Flagstaff of 1923 honors soldiers and sailors of the First World War.

The towers around the square

Madison Square is ringed by landmarks worth a slow walk. On the east side rises the Met Life Tower, in whose girders a newspaper once installed a searchlight to signal election results in 1908. North of it stands the gilded pyramid of the New York Life Building, built on the site of the old Madison Square Garden.

Between the two, the small marble Appellate Division Courthouse faces the park across Madison Avenue, a quieter building than its neighbors but worth a look for its own ornament and setting. Together with the Flatiron Building itself, these structures make the square one of the most architecturally varied corners in Midtown.

None of these buildings are far from one another, and the park makes a natural base for walking the loop. Benches throughout the square offer views of all of them at once, which is as good a reason as any to slow down here rather than photograph the Flatiron and move on.

How to visit

The plaza, the park, and the view of the building are all free to enjoy, and the park is a reasonable place to sit with lunch; the Shake Shack burger stand here opened in 2004. Allow roughly half an hour for the square and the building itself, longer if the landmarks around its edges are added to the walk.

Several subway lines stop at 23rd Street along both Broadway and Park Avenue; check current routes and any service changes with the MTA before setting out, and see Getting Around for general guidance on the subway system. The Flatiron district also makes a convenient base for a stay in Manhattan.

From the plaza, Fifth Avenue leads north to the Empire State Building at 34th Street, covered at The Empire State Building, or south toward Washington Square. Walking west along 23rd Street leads to the High Line, described at The High Line, for a different view of how Manhattan's older infrastructure has been reused.