The interior had a T-shaped atrium open to the public, with retail space, a lobby extending from Fifth Avenue, and a waterfall sculpture by Isamu Noguchi.

Described in The New York Times as the world's largest aluminum curtain wall,[19] it consisted of nearly 3,000 spandrel panels,[a] which were installed between windows on different stories.

[23] Before the original aluminum curtain wall was removed, Brookfield Properties' construction director said that occupants could feel wind coming through the panels because they were so porous.

[28][18] Described by the Real Estate Record and Guide as a "Tower of Light",[29] the system consisted of 72 reflector lamps mounted on the building's setbacks.

[18] The refrigeration plants were described by The New York Times as having a similar cooling capacity to sixty thousand ice blocks weighing 100 pounds (45 kg) each.

Made of structural glass and lit by hidden spotlights, the waterfall wall was crossed by stainless steel fins that extended the entire height of the lobby.

Starrett & van Vleck would have developed a new Lord & Taylor flagship store on the site, replacing an existing structure at Fifth Avenue and 38th Street.

At the time, the existing store did not have enough space for Lord & Taylor's operations, and the company planned to build a skyscraper with a new flagship at the first ten stories.

Early plans called for using 6-foot (1.8 m) wide windows separated by 2.5-foot (0.76 m) limestone piers, significantly wider than the 4.5-foot (1.4 m) vertical divisions that were then commonplace.

[83][84] Tishman Realty obtained title to the new building's site in May 1955 from Lord & Taylor parent company Associated Dry Goods.

Steelworker Larry Weinmann, a former cartoonist, put cartoon decorations and depictions of the completed building onto the construction fence, and boxes of geraniums with notes of appreciation were placed outside the worksite in 1956.

The association praised the building's simple form, embossed facade spandrels, steel mullions, and exterior lighting system.

[125] In 2004, Tishman Speyer obtained a $562.5 million, five-year commercial mortgage-backed security (CMBS) senior loan from Lehman Brothers and UBS, which was split into three pari passu notes.

[127] After Charles Kushner was jailed in 2005, his son Jared took over the family company,[130] moving the headquarters from Florham Park, New Jersey, to 666 Fifth Avenue.

[9] At the end of 2011, Kushner brought in Vornado Realty Trust which purchased a 49.5 percent equity stake for $80 million and assumed half the building's debt.

[139] Kushner also agreed to invest another $30 million for leasing the building's vacant space, which comprised 30 percent of the floor area, and rework it to suit tenant needs.

[143] Barrack claimed to have arranged the meetings and said a tentative deal for a $500 million equity investment fell apart after Donald Trump won the 2016 United States presidential election.

[143] Saudi Arabian billionaire Fawaz Alhokair and the South Korean state-owned sovereign wealth fund Korea Investment Corporation were among the other potential investors.

The upper floors would be converted to luxury condominiums, while the Kushners would invest $750 million in the retail space, ending up with a 20 percent stake in the project.

[149][150] Some of the alleged terms of the deal were called "unusually favorable", including an exit for Vornado Realty Trust and retirement of the Kushner organization's remaining debt.

[149] These concerns led a group of Democratic politicians[f] to send a letter to Steven Mnuchin, the U.S. Treasury Secretary, demanding an investigation by the Committee on Foreign Investment in the United States.

[152] The failure of the Anbang agreement prompted Zaha Hadid Architects to design a $12 billion, 1,400-foot (430 m) skyscraper on the site, which would have been the world's third most expensive building.

[147] The structure, to be completed by 2025, would have contained a "vertical mall" on its lowest nine floors, topped by an 11-story hotel and 464,000 square feet (43,100 m2) of high-end condominiums.

[153][154] To raise money for the tower, Charles Kushner met with Qatari Finance Minister Ali Sharif Al Emadi in April 2017.

[155] The meeting came roughly one month before the Qatar diplomatic crisis began; Jared Kushner reportedly sided with Saudi crown prince Mohammad bin Salman against Rex Tillerson, the U.S. Secretary of State.

[143] The unsuccessful talks, the project's exorbitant costs, and the risks of the ultra-luxury condominium market prompted Vornado's Steven Roth to push for a more modest office renovation.

[169] The purchase attracted controversy since the Qatar Investment Authority (QIA) owned a 9 percent stake in Brookfield Property Partners.

[201] The computer-service company Donovan Data Systems, time-share firm Keydata Corporation, theater chain Loews Cineplex Entertainment, and brokers Shearson all leased space in the building in 1979.

[234] In 2011, Japanese retailer Uniqlo signed a 15-year, $300 million lease for 89,000 square feet (8,300 m2) of space at the base of the building,[235] beating out other potential lessees including Topshop, Nordstrom Rack, and AllSaints.

The storefronts of the Hollister flagship were fitted with a live video feed from Huntington Beach, California, displayed along with wave pools on 179 flat-screen TVs.