The Downtown Crossing MBTA station is one of the more important subway stations in Boston. It is surrounded by a large commercial district and is a juncture between the Red and Orange lines of the MBTA. The station tends to be extraordinarily busy at all hours of the day, as the Red and Orange lines serve both downtown Boston and the suburbs. There is a little-known but extremely useful concourse (MBTA-speak for filthy underground passage) that connects Downtown Crossing to the even-more-heavily-traveled Park Street station, allowing free transfers between the Red, Orange, and Green lines. This station is best avoided when alone late at night, as it is located near the Combat Zone, and the Orange Line serves some fairly high-crime neighborhoods. It should be noted that embarcation from Downtown Crossing renders the prospect of finding a seat ridiculous at best.