The London Underground, also known as the Tube, is a public rapid transit system serving Greater London and parts of the surrounding counties. It is one of the oldest and largest underground railways in the world, with 11 lines and over 270 stations. The Tube is operated by Transport for London (TfL) and carries millions of passengers each day.The history of the London Underground dates back to the mid-19th century when the Metropolitan Railway, the world's first underground railway, opened in 1863. Over the years, more lines and stations were added, and the network expanded to cover the entire city and beyond.Today, the Tube is a crucial part of London's transportation system, connecting various parts of the city and making it easy to travel around. It is a popular mode of transport for commuters, tourists, and residents alike.The London Underground is known for its distinctive roundel logo, which features a red circle encompassing a blue bar with the name "London Underground" written across it. The Tube map, designed by Harry Beck in 1931, is another iconic symbol of the system, with its simplified, geographically distorted layout.The Tube operates from early morning to late at night, with trains running at regular intervals. The system is known for its reliability, although occasional delays and disruptions can occur. The Tube is especially busy during rush hours, when commuters pack the trains to get to and from work.Overall, the London Underground is a vital part of London's infrastructure and plays a significant role in the daily lives of its residents and visitors. It is an efficient and convenient way to get around the city and explore its many attractions.