The Brussels Metro (, ) is a rapid transit system serving a large part of the Brussels-Capital Region of Belgium. It consists of four conventional metro lines and three "premetro" lines. The metro-grade lines are M1, M2, M5, and M6 with some shared sections, covering a total of , with 59 metro-only stations. The "premetro" network consists of three tram lines (T3, T4, and T7) that partly travel over underground sections that were intended to be eventually converted into metro lines. Underground stations in the "premetro" network use the same design as metro stations. A few short underground tramway sections exist, so there is a total of of underground metro and tram network. There are a total of 69 metro and "premetro" stations as of 2011.