If subway stops for just an hour, transport will come to a standstill. The world's first metro line opened in London on January 10, 1863. It was 3.6 km long and had 7 stations. The subway construction was conducted by «Metropolitan Railways». In fact, the word "metro" widely used today in many countries, was derived from the company’s name “Metropolitan”. However, Londoners call their subway «tube» (translated from English as "pipe") because of its round and rather narrow tunnels.