London's underground system has been in operation since 1863 and is the world's oldest subway system. The "Tube," as it is called in London, connects travelers to Heathrow Airport, local train stations, buses and major destinations throughout the city. Visitors can obtain free underground maps and travel information at any ticket center. The Tube operates on 12 lines and runs between 5 a.m.-midnight with limited hours on Sundays.
The New York City subway was founded in 1904 and transports 4.9 million people daily. The Metropolitan Transit Authority administers the operation of New York's subway system. With 462 stations, New York's subway system has one of the most extensive transit lines in the world. Grand Central Terminal is a landmark and one of New York city's oldest rail stations.
In addition to providing heated seats and announcements in English and Japanese, Tokyo's subway system offers shopping at various underground malls. The subway trains also connect travelers to the suburbs of Tokyo. One-day passes or single tickets can be purchased at automated gates at each station.
Madrid's clean energy subway is the second largest underground system in Europe. Madrid's "Metro" operates in 294 stations and is equipped with ramps, elevators and escalators for easy access. The Metro has also expanded its operations by adding new lines and upgrading existing facilities.
