Two duplex apartments at the One57 condo tower have sold for more than $90 million each -- a staggering number even in Manhattan’s super-luxe market.

One57, just steps from New York’s Carnegie Hall, is not only crazy expensive, it’s super-tall for a residential building.

Designed by Paris architect Christian de Portzamparc, the tower rises to 1,000 feet, with panoramas of Central Park and midtown Manhattan.

The new building is one of perhaps a dozen needle-thin towers planned for New York. Carol Willis, the founder of Manhattan’s Skyscraper Museum, calls them “a new type in the history of the skyscraper.”

Super-slims are unique to Manhattan. “The economy of land values drives what can be built,” Willis said.

“Sky High and the Logic of Luxury,” an exhibition now on view at the museum makes that case with models, floor plans and diagrams of acrobatic engineering.

In buildings with just one sprawling residence per floor, the owner shares the views only with passing falcons.

You would think these towers would cast deep shadows for blocks around, but their skinniness minimizes the gloom.

The staggering price tags and a perception (possibly fanciful) that the universe of global billionaires is big enough to support a few hundred more units have developers rushing to erect super-slims. The competition for the best views is fierce.

Here’s my street-level assessment of the three 57th Street needles: