Vessel's 2,400 steps will anchor the largest private development in the U.S., lifting visitors above Hudson Yards' 14 acres of parks and plazas. The elevations will give New Yorkers and tourists—siphoned off a to-be-constructed High Line spur—a place to view each other and all the stalagmitic towers of Hudson Yards. When complete, the 16-story structure will be the tallest freestanding observation platform in the city, at least until Staten Island's New York Wheel starts rolling.