The Tbilisi Metro serves the city with rapid transit subway services. 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 22 stations and 186 metro cars. Most stations, like those on other 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 level in some areas. Two of the stations are above ground.