Piața Unirii (Union Square) is a major metro station in Bucharest. It is located in the southern part of the city centre, in Union Square (Piața Unirii in Romanian), and it is one of the busiest stations of the Bucharest Metro. It is made up of two terminals, one on the M1 and M3 lines and another on the M2 line, linked by a passage. The M1/M3 station was opened on 19 November 1979 as part of the inaugural section of Bucharest Metro, between Semănătoarea and Timpuri Noi. The M2 station was opened on 24 January 1986 as part of the inaugural section of the line, from Piața Unirii to Depoul IMGB. On 24 October 1987, the line was extended north to Pipera.