The document discusses the Moscow subway system, noting that it has 138 stations and is over 256 km long. It began construction in 1930 and its stations near the city center are some of the most beautiful, resembling museums or palaces with grand marble decorations depicting important events in Russian history. During World War II, the deep stations offered shelter from aerial bombings. New stations continue to be built further out as the lines expand. The system has 9 color-coded lines and operates from 5:30am to 1:30am with trains running every 1 minute or less during busy times.