NEW YORK — New York City is a city of epic skyscrapers, but one ambitious architect has a big U-shaped vision for the skyline that would be the longest building in the world if built.

His proposal, unveiled Thursday, calls for a slender, U-shaped tower that would be longer than it is tall, packing in lots of pricey square footage while doing an end run around restrictive zoning regulations.

Called "The Big Bend," the tower would be located on 57th Street, also known as Billionaire's Row for the luxury apartment towers that continue to sprout along the boulevard, including One57.

"The Big Bend can become a modest architectural solution to the height limitations of Manhattan," architect Ioannis Oikonomou's design studio, Oiio, posted on its website.

The proposal for the 4,000-foot-long building wouldn't require going anywhere near that tall — a tower of that height would be an extraordinary sight, almost three times as tall as the roofline of One World Trade Center.

"New York City’s zoning laws have created a peculiar set of tricks through which developers try to maximise their property’s height in order to infuse it with the prestige of a high rise structure. But what if we substituted height with length? What if our buildings were long instead of tall? If we manage to bend our structure instead of bending the zoning rules of New York we would be able to create one of the most prestigious buildings in Manhattan," the Oiio studio said.

The concept building is just that — a bold idea designed to captivate. Whether it is ever built is an entirely different question.