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.

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.

The second time, on 1 May 1987, the station was again flooded, when, during construction works on the nearby Unirii Underpass, an excavator breached a canal of the Dâmbovița.

Because the canal that was breached mainly hosted wastewater, it left a horrible smell in the station, which further hampered cleanup efforts.