T-Centralen in the context of "Yellow line (Stockholm Metro)"

The Stockholm Metro (Swedish: Stockholms tunnelbana) is a rapid transit system in Stockholm, the capital city of Sweden. Its first line opened in 1950 as the first metro line in the Nordic countries. Today, the system consists of three lines and 100 stations, of which 47 are underground and 53 above ground. The system is owned by Region Stockholm via SL, the public transport authority for Stockholm County. It is the only metro system in Sweden.

The metro's three coloured lines, Green, Red, and Blue, together form seven routes with different termini. All of these routes pass through the city centre, creating a highly centralised network. The main interchange for all three lines is T-Centralen station, where they intersect. In addition to T-Centralen, the system has three other interchange stations: Fridhemsplan, Slussen, and Gamla stan. Various extensions to the system are currently under construction, An extension to the north-west of Blue Line is expected to open in 2027, while extensions to its south are expected to open in 2030. Construction of a new Yellow Line to the west of the city centre is scheduled to start in 2025.

The Blue line (Swedish: Blå linjen; officially Metro 3, but called Tub 3 ("Tube 3", or abbreviation for "Tunnelbana 3") internally) is one of the three Stockholm Metro lines. It is 25.5 kilometres (15.8 miles) long, and runs from Kungsträdgården via T-Centralen to Västra skogen where it branches in two, and continues to Hjulsta and Akalla as lines 10 and 11 respectively.

Slussen is a station on the Stockholm metro and Saltsjöbanan, located at Slussen in the district of Södermalm. The metro station is served by the Red and Green lines, and originally opened in 1933 as an underground tram stop, on 1 October 1950 it became the terminal of the first metro line running south to Hökarängen, it was again rebuilt when the extension of the line north to Hötorget was opened on 24 November 1957. On 5 April 1964, the first stretch of the Red line, between T-Centralen and Fruängen, was opened.

Slussen has also been the terminus for the Saltsjöbanan railway since the 1940s, however this has temporarily been moved to Henriksdal in 2016 due to the reconstruction of Slussen. Traffic will resume when the reconstruction is complete due in 2028. Just outside the northern entrance to the metro station, there is a bus terminal for buses to the Nacka and Värmdö municipalities.