The Tbilisi Metro serves the city with rapid transit subway services. More than 400 thousand journeys are made on the system every single day. It was the Soviet Union's fourth metro system. Construction began in 1952 and was finished in 1966. The system operates two lines, the Akhmeteli-Varketili Line and the Saburtalo Line. It has 23 stations and 186 metro cars. Most stations, characteristic to Soviet-built metro systems, are extravagantly decorated. Trains run from 6:00 am to midnight. Due to the uneven ground, the rail lines run above ground in some areas. Two of the stations are above ground.