Riding the public transit system (known as the "T") is one of the best ways to get around Boston. The four subway lines are designated by colors, Red, Blue, Green and Orange, and the lines intersect at several points downtown. Passengers can transfer between lines free of charge. To find stations, look for circular white signs with a black "T." The base fare for the subway system is USD1. The MBTA Visitor Pass allows unlimited transportation for a single fee. There are also rail lines to the suburbs, bus routes and boat routes. See the Web site for details.