[8] In September 1961, the Port of New York Authority announced that it would erect an exhibition building and heliport on a 1.25-acre (0.51 ha) land lot in the fair's transportation section.

[14] In the middle of that year, Knott Hotel Corporation agreed to operate the pavilion's restaurant, which was to be called Top of the Fair[13][15] and occupy two stories.

[16] The Port Authority awarded a general construction contract for the heliport to the W. J. Barney Corporation in November 1962 for $3.7 million, having rejected seven other bids as too expensive.

[18] Niles Communications Centers Inc. created a 360-degree film of New York City for the pavilion,[19] using a rig with 10 cameras to collect footage from trucks, boats, and helicopters.

[20] United Aircraft was also hired to operate the building's heliport;[21][22] it would pay the Port Authority $750,000, plus a portion of any revenue exceeding $2.6 million.

[23][24] The Port Authority Building opened on October 16, 1963, with a ceremony attended by hundreds of people;[25][26] it was the first completed structure on the World's Fair site.

[30] The restaurant started receiving guests while the rest of the fairground was being developed,[26][31] but the exhibit at the building's ground level remained closed until the beginning of the fair.

[34] The WFC anticipated that the vast majority of fairground visitors would arrive by car, bus, taxi, or train, with a negligible number using the heliport or the World's Fair Marina.

[36] The World's Fair formally opened on April 22, 1964,[37][38] but New York Airways' flights from the building did not begin for another five days because of bad weather.

[55] The dishes served at the restaurant initially included oysters, liver, crab ravigote, and assorted hors d'oeuvres.

[57] The WFC initially anticipated that the Port Authority pavilion's restaurant would accommodate up to 30,000 visitors a day,[24][25][53] and Moses often held receptions for guests there.

[20] That June, as part of an agreement between New York Airways and Trans World Airlines, helicopters began operating between the Port Authority Pavilion and the TWA Flight Center at JFK Airport.

[62] By mid-1964, diners had complained about Top of the Fair's poor service and high prices,[63] and the restaurant faced competition from more than a hundred other eateries on the fairground.

[66] After the fair's first season ended on October 18, 1964,[67] the restaurant atop the Port Authority Pavilion was supposed to have continued operating during the off-season.

[54] Top of the Fair's revamped menu included hors d'oeuvres such as salad, shrimp, and beans; a course of soup; and a variety of entrees such as stuffed flounder, lamb, ribs, and steaks.

[80] By that July, Top of the Fair had stopped serving luncheon meals due to a lack of patronage, and it began operating only during suppertime.

[82] The heliport's patrons included Princess Benedikte of Denmark,[83] as well as rock band The Beatles, whose helicopter landed there prior to their August 1965 concert at Shea Stadium.

[91] When the fair ended, Baum wanted to continue operating the restaurants and convert the ground-floor space to an event venue.

[77] The Terrace Club and Top of the Fair remained open under an informal gentlemen's agreement and a two-year contract with the WFC.

[84] Another notable event at the building, a party for the Ghanaian king Otumfuo Nana Osei Tutu II, included women dancing barefoot.

[101] The project included dividing the original restaurant into several smaller spaces,[49] and the new operators constructed an additional ballroom named the Penthouse on the old heliport.

[113] Even though the Levins' lease required them to open the building to the public, Terrace on the Park was operating exclusively as a catering venue by the 1980s.

[116] The same year, NYC Parks leased the building to Crystal Ball Group,[116] whose executives included George Makkos and his brother Thomas.

Because of Queens's extremely high ethnic diversity, the venue served a wide variety of cuisine, in addition to kosher and halal food.

Every year, the firm pays the New York City Department of Parks and Recreation either 20% of its gross receipts or $2.5 million, whichever is greater.

[132] Other structures in the park, such as the Unisphere, USTA Billie Jean King National Tennis Center, and Citi Field, are visible from the top of the building.

[136] Luis Quintanilla designed three murals for the main part of the restaurant,[24][136] and watercolors and engravings were exhibited in the Terrace Club.

[26] When the World's Fair was in operation, the cocktail lounge was placed on the circumference of the floor, and there were two rows of tables arranged around a circular aisle.

[141] Writing retrospectively about the fair in 2007, Lawrence R. Samuel described the Port Authority Pavilion as "another symbol of [Moses's] status as a power broker for half a century".

[84] Joseph Tirella, in another retrospective of the World's Fair, said that the building was "a modernist rectangular box" and that the original restaurant had been "much maligned".