Oiio

New York City Architecture firm Oiio has proposed a conceptual skyscraper that would curve at the top and then return to the ground, becoming what the firm believes to be the “longest” building to ever be created. As reported by dezeen, their "Big Bend" proposal challenges Manhattan’s obsession with supertall skyscrapers by substituting extreme height with length—stretching 4,000 feet from end to end. If they are able to design this building, Oiio hopes it could potentially provide a solution to the height limitations imposed by city zoning laws.
See the renderings here