Chicago Union Station  Chicago Union Station is an intercity and commuter rail terminal located in the West Loop Gate neighborhood of Chicago, Illinois. The station serves as Amtrak's flagship station in the Midwest, serving intercity trains, and is also the downtown terminus for six Metra commuter lines. The station stands on the west side of the Chicago River between West Adams Street and West Jackson Boulevard, just outside the Chicago Loop. Including approach and storage tracks, it covers about nine and a half city blocks (mostly underground, buried beneath streets and skyscrapers). Chicago Union Station opened in 1925, replacing an earlier station built in 1881. The station is the fourth-busiest rail terminal in the United States, after Pennsylvania Station, Grand Central Terminal, and Jamaica station in New York City. It is Amtrak's overall fourth-busiest station, and the busiest outside of its Northeast Corridor. It handles about 140,000 passengers on an average weekday (including 10,000 Amtrak passengers) and is one of Chicago's most iconic structures, reflecting the city's strong architectural heritage and historic achievements. It has Bedford limestone Beaux-Arts facades, massive Corinthian columns, marble floors, and a Great Hall, all highlighted by brass lamps. Chicago Union Station provides direct connections to multiple transit authorities including the Chicago Transit Authority bus and Chicago L lines, Metra, Pace, Greyhound, and more within the station or within walking distance. Chicago Union Station is named a union station, like many train stations across the United States that were shared by several railroad companies. The station is the third union station to occupy the site between West Adams Street and West Jackson Boulevard. The station is known by the acronym CUS, as well as by its Amtrak station code CHI. Chicago Union Station is situated in the West Loop Gate neighborhood of the Near West Side of Chicago, just west of Chicago's downtown. The station's underground concourse and train sheds abut the Chicago River; passageways extend west beneath Canal Street to the main station building, one block over. Unlike many major American intercity and commuter rail hubs, Union Station does not have any direct connection to local rapid transit service. However, two Chicago "L" stations are within walking distance of Union Station. Metra's other three downtown terminals – the Ogilvie Transportation Center, LaSalle Street Station and Millennium Station – are all within walking distance of Union Station. Passengers connecting from Ogilvie can access Union Station's north platforms on the opposite side of Madison Street.