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 in the city center are known for their beautiful architecture and decorations depicting important events in Russian history. During World War II, the deep subway stations offered shelter to Moscow residents from aerial bombings. The system continues to expand further into suburbs with newer, more soberly designed stations. It operates daily from 5:30 am to 1:30 am with trains running every 1 minute or less during busy times.