The tower, designed by Skidmore, Owings and Merrill (SOM), cost US$3.9bn (€3.6bn, £2.6bn) to develop / One World Trade Center

The One World Observatory at New York’s One World Trade Center building will open its doors to the public at the end of May, with tickets now on sale, enabling the public to visit the top of the western hemisphere’s tallest skyscraper.

The building, which is largely office space, welcomed its first tenants – Condé Nast – in November 2014, 13 years after the 9/11 terror attacks.

The tower, designed by Skidmore, Owings and Merrill (SOM), cost US$3.9bn (€3.6bn, £2.6bn) to develop. Tishman Realty & Construction – the firm that built the original World Trade Centers destroyed in the 9/11 attacks – led the construction team for the new development.

SOM’s design uses the sun to create a kaleidoscope effect on the building’s exterior, with the varied outer glass surfaces changing appearance depending on light and weather conditions. Development of the One World Observatory on floors 100-102 started in early 2014 and when it opens on 29 May the One World Observatory is expected to welcome millions of visitors each year.

The Hettema Group are behind the design of the 120,000sq ft (11,148sq m) observation deck and accompanying experience. Legends Hospitality was chosen in 2013 by The Port Authority Board of Commissioners to run the attraction, which sits at the top of New York’s skyline.

"They wanted something unique," said a spokesperson for Hettema speaking to AM2 about the brief from the Port Authority. "They wanted it to compete with the other observatories in the market and it was an early goal not to focus on 9/11 as this was more about the future and the vibrancy and resiliency of New York City."

The experience starts from on the floor, where visitors walk along a multi-sensory passageway telling the story of the new World Trade Center’s construction. The walkway will feature soundbites, along with messages incorporating historical facts and statistics about the building's structure and foundations.

From there, visitors will board one of five state-of-the-art glass elevators – among the fastest lifts in the world – which will take them up 1,268 ft (386.5 m) to the 1,792 ft (546.2 m) tower’s top floor. The “Skypod” elevators give riders the virtual experience of being outside the building, with New York seemingly rising up from the ground as they make the 60 second ascent.

The attraction will feature a series of multimedia exhibits, presenting One World Trade Center as a “global nexus of 21st-century commerce, culture and community, set in the heart of the most dynamic international city in the world”. Included on the observation deck are several dining options, a gift shop, a 9,300sq ft space for special events and the “See Forever” theatre where visitors will learn about the construction of the building.

The observatory also features the Sky Portal where guests can step onto a 14-foot wide circular disc that will deliver a real-time, high-definition view of the streets below.