It is the fifth-busiest transportation hub in the New York metropolitan area. The transportation hub connects the various modes of transportation in Lower Manhattan, from the Fulton Center in the east to the Battery Park City Ferry Terminal in the west, and includes connections to various New York City Subway stations. The interior of the station house contains two underground floors, which house part of the Westfield World Trade Center mall. The $4 billion Oculus station house, designed by the Spanish architect Santiago Calatrava, consists of white ribs that interlock high above the ground. The New York City Subway's WTC Cortlandt station is adjacent to and above the mezzanine. The floor immediately above the platforms is occupied by the station's fare mezzanine. The platforms are located four floors below ground level. Trains from New Jersey use the loop to turn around and head back to New Jersey. The World Trade Center station has five tracks and four platforms in the middle of a turning loop. The main station house, the Oculus, opened on March 3, 2016, and the terminal was renamed the World Trade Center Transportation Hub, or "World Trade Center" for short. Work on a permanent station building commenced in 2008. Following the Septemattacks, a temporary PATH station opened in 2003 while the World Trade Center complex was being rebuilt. The World Trade Center station opened on July 6, 1971, as a replacement for Hudson Terminal, which was closed and demolished as part of the construction of the World Trade Center. The Port Authority of New York and New Jersey bought the bankrupt H&M system in 1961, rebranded it as PATH, and redeveloped Hudson Terminal as part of the World Trade Center. The World Trade Center station is near the site of the Hudson and Manhattan Railroad (H&M)'s Hudson Terminal, which opened in 1909.