After 12 years of planning, designing, and construction, the World Trade Center Transportation Hub opened its doors last week. And it looks a lot like a gleaming white bird in flight (or tail or a whale, depending on who you’re talking to). The 800,000 square-foot structure, which officially opened on Thursday, is striking amidst the dark skyscrapers of New York City’s downtown Financial District.

The building could very well be a living creature. At least it’s described as one by architect Santiago Calatrava who designed the $4 billion skeletal structure after a bird released from a child’s hands. “I was trying to do something very light and atmospheric,” Calatrava told New York magazine back in March 2015. “Where the sky and the firmament is real.”

The steel ribs make up an elliptical dome, the oculus, while the spine of the building is a large, glass, retractable skylight that will open on temperate days and every September 11. The white steel railings and symmetrical curves are a signature of Calatrava’s — the style can also be seen in his design for the Chicago Spire Tower and train station in Reggio Emilia, Italy.

It’s the third largest train station in New York City and the most expensive in the world. Sandwiched between One World Trade Center and St. Paul’s Chapel, the hub is a stop for the Port Authority Trans-Hudson (PATH) rail system and New York City 1, A, C, and R subway lines.

Currently, only the main floor is open to the public, but the Port Authority predicts that the hub will eventually serve 250,000 daily commuters.

Check out 50 of the best images of the Oculus Train Station below.

Calatravas #calatravasnyc #NYC #fidi #manhattan #downtown #wtc #wtctrainstation #wow

A photo posted by Darren (@dlnnyc64) on

Looking up at #1WTC and #7WTC on opening day of the #WTC Transportation Hub

A photo posted by World Trade Center (@wtc) on

Shiny #worldtradecenter #worldtradecenterstation #NY #NYC #path #nysubway #newjersey

A photo posted by Ruth Emily (@ruth.emily) on

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#worldtradecenterstation

A photo posted by taranique04 (@taranique04) on

#Calatrava #worldtradecenterstation #nyc

A photo posted by Love Liljeqvist (@lovelilje) on

#NYC. #newyork. #worldtradecenter. #worldtradecenterstation

A photo posted by Marc Cooke (@marcooke) on

Old Glory

A photo posted by Meagan Rachman (@rachman_photography) on

Photo by Michael Lee/Getty Images
Photo by Michael Lee/Getty Images
Construction in August 2015. Photo by Anthony Quintano
Construction in August 2015. Photo by Anthony Quintano

Progress #worldtradecenterstation #calatrava #birdsofafeather #freedom

A photo posted by Yoania Reyes (@y_del_carmen) on

Photo by Billie Grace Ward, taken on September 11, 2015
Photo by Billie Grace Ward, taken on September 11, 2015
Photo by Billie Grace Ward
Photo by Billie Grace Ward
Cranes assemble the steel railings on July 27, 2015. Photo by Billie Grace Ward
Cranes assemble the steel railings on July 27, 2015. Photo by Billie Grace Ward
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Photo by Billie Grace Ward
Photo by Billie Grace Ward
Photos via Spencer Platt/Getty, Michael Lee/Getty Images, Anthony Quintano, Billie Grace Ward, Billie Grace Ward/Flickr, Wikimedia Commons