Metro do Porto is a light rail network that runs underground in central Porto and above ground into the city's suburbs. Metro do Porto S.A. was founded in 1994, and the first line of the system opened in 2002. The network has 6 lines and reaches seven municipalities within the metropolitan Porto area: Porto, Gondomar, Maia, Matosinhos, Póvoa de Varzim, Vila do Conde and Vila Nova de Gaia. It currently has a total of 81 operational stations across 67 kilometres of double track commercial line.