A Subway That Never Stops Running

New York City's subway system, which opened in 1904, is one of the few major transit systems in the world that operates 24 hours a day, seven days a week, 365 days a year. It has 472 stations, more than any subway system on earth, spanning 245 miles of routes under and over a city of 8 million people. The system carries about 3.5 million riders on an average weekday. Each year, the lost and found at the New York Transit Museum recovers thousands of items left on trains and platforms, including on one notable occasion a full set of encyclopedias.

Source: Wikipedia