Unlike most of New York City’s standout architecture, this sculptural, almost alien-looking structure set to rise above the new Hudson Yards development will be open for the public to explore. Architect Thomas Heatherwick envisions this centerpiece as a way to take all of the visitors to the square and “sort of sprinkle them into the air,” encouraging them to interact with each other and with their surroundings in a new way.

Influenced by images of Indian stepwells, which use hundreds of flights of stairs to descend beneath ground level, this observation deck uses flights of stairs almost like building blocks to reach into the sky.

The ‘Vessel’ design is made up of 154 interconnecting flights of stairs, with nearly 2,500 individual steps and 80 landings, and if you want to walk the whole thing, you’ll travel an entire mile while remaining in the air above Hudson Yards. It’s 50 feet in diameter at the feet, blooming into 150 feet at the top, and gleams appealingly in polished copper.

The square at Hudson Yards is a collaboration between Heatherwick Studio and landscape architecture firm Nelson Byrd Woltz, set to feature 5 acres of trees, perennial gardens, pathways, seating and a 200-foot-long fountain mimicking a flowing river.

The square will be surrounded by a whopping 16 brand new skyscrapers containing nearly 13 millions square feet of office, residential and retail space. The largest development in New York City since Rockefeller center was built in 1939, it’s currently under construction, and estimated to be fully completed by 2023.

“We put ourselves under this vast pressure because we felt, intuitively, that it should be something that you haven’t experience already before,” says Heatherwick. “It has no commercial job to do. It’s not based on electronics. It’s not based on advertising. it’s extremely interactive but it’s properly using your physicality. There’s something that is timeless about humans and our physicality. The project, in a way, is a big invitation. It’s just there to hopefully mean things to different people, to not tell you how you’re supposed to think. It’s like a platform for life.”