Designed by Heatherwick Studio, Vessel is a new type of public landmark ? a 16-storey circular climbing frame, with 2,465 steps, 80 landings and views across the Hudson River and Manhattan. It is the central feature of the main public square in the Hudson Yards development, one of the largest real estate projects in American history, which is transforming a former rail yard in Manhattan?s Upper West Side into a completely new neighbourhood, with more than five acres of new public spaces and gardens.

Heatherwick Studio was asked to design a centrepiece for Hudson Yards, something that would welcome visitors into the heart of the district and create a new place to meet in Manhattan. Part of the challenge was to create something memorable that would not be overwhelmed by the surrounding cluster of towers, or the scale of the new public space above the train platform. Exploring different possibilities, the team started to narrow the parameters: it should be a memorable single object, not a series of objects dispersed throughout the space; rather than an inert, static sculpture, it should be a social encounter, which encourages activity and participation ? it should be fun.
By opening up voids between the steps to create a three- dimensional lattice, the public square could be stretched upwards, creating more than a mile of routes that could be explored in different ways. To create the continuous geometric pattern of the stepwell, with 154 interconnecting flights of stairs, th...