There are four railroad properties in the Monopoly board game: Pennsylvania Railroad, B&O Railroad, Reading Railroad and Short Line Railroad. All four railroads are based off of various train routes in the United States.
Monopoly is a board game where players attempt to buy properties around the board and complete different colored sets of properties. In addition to properties, players can also buy utility properties and railroad properties. The four railroad properties cost $200 each. When players land on a railroad that is owned, they must pay the player who owns it. The amount they must pay depend on how many railroad properties the owner has.