Small Ring, Brussels in the context of Arts-Loi/Kunst-Wet metro station

Line 2 is a rapid transit line on the Brussels Metro in Belgium operated by STIB/MIVB. It has existed in its current form since 4 April 2009, when the section between Delacroix and Gare de l'Ouest/Weststation was opened, which allowed to close the "loop" from and to Simonis/Elisabeth. The configuration of Simonis/Elisabeth though does not allow trains on line 2 to perform the loop several consecutive times in the same direction, i.e. a train running clockwise from Elisabeth will have to run counterclockwise from Simonis. The two termini of line 2 have thus received different names: originally Simonis (Elisabeth) and Simonis (Leopold II), changed in November 2013 to Elisabeth and Simonis. Between Yser/IJzer and the Porte de Hal/Hallepoort, the line runs under the Small Ring (Brussels' inner ring road), which was itself built on the site of the former second walls of Brussels. The line crosses the municipalities of Koekelberg, Molenbeek-Saint-Jean, City of Brussels, Saint-Gilles and Anderlecht.

The first stations on the Small Ring were opened in 1970 with tramways connecting Rogier to Porte de Namur/Naamsepoort. Louise/Louiza was opened in 1985 and Simonis in 1986, but it was only in 1988 that the actual metro line 2 was first serviced with metros. The following stations also opened that year: Ribaucourt, Yser, Hôtel des Monnaies/Munthof, Porte de Hal and Gare du Midi/Zuidstation. The existing stations were converted in order to be serviced by metros. In 1993, the line was expanded to Clemenceau, and then to Delacroix in 2006. The route of line 2 is also currently served by line 6, which then continues from Simonis to Roi Baudouin/Koning Boudewijn.

Line 6 is a rapid transit line on the Brussels Metro in Belgium operated by STIB/MIVB. It connects Roi Baudouin/Koning Boudewijn in the north-west of Brussels to Simonis/Elisabeth to the north-west of the city centre, then performing a counterclockwise "loop" around the centre up to Simonis again. During this loop, the line runs under the Small Ring (Brussels' inner ring road), from Porte de Hal/Hallepoort to Yser/IJzer. It has existed in its current form since 4 April 2009, when it replaced former line 1A between Roi Baudouin and Beekkant. It serves 25 metro stations and has 26 stops, metros on that line stopping twice at Simonis. The Simonis-Elisabeth loop is also served by line 2. The line has also a common section with lines 1 and 5 between Gare de l'Ouest/Weststation and Beekkant. A connection with those lines is also possible at Arts-Loi/Kunst-Wet. Starting from Roi Baudouin, the line crosses the municipalities of the City of Brussels, Jette, Koekelberg, Molenbeek-Saint-Jean, Anderlecht and Saint-Gilles.

The Pentagon (French: Pentagone, pronounced [pɛ̃taɡɔn] ; Dutch: Vijfhoek, pronounced [ˈvɛifɦuk] ) or Brussels' city centre is the historical city centre of Brussels, Belgium, within the contours of the Small Ring inner ring road. The Small Ring is located on the site of the second walls of Brussels, which were built in the 16th century. As in most European cities, these walls were replaced by large boulevards at the end of the 19th century.

The Pentagon, within the Small Ring, covers 4.61 km (1.78 sq mi) and is more or less pentagonal or heart-shaped, hence its name. In 2013, 51,566 people lived there, mainly in the Marolles/Marollen district and west of the central boulevards. For the entire City of Brussels, there were 168,576 inhabitants; the majority living outside the Pentagon, in the northern part of the municipality.

The Leopold Quarter (French: Quartier Léopold, pronounced [kaʁtje leɔpɔl(d)]; Dutch: Leopoldswijk, pronounced [ˈleːjoːpɔltsˌʋɛik] ) is a quarter of Brussels, Belgium. The term is sometimes confused with the European Quarter, as the area has come to be dominated by the institutions of the European Union (EU) and related organisations, although the two terms are not in fact the same, with the Leopold Quarter being a smaller more specific district of the municipalities of the City of Brussels, Etterbeek, Ixelles and Saint-Josse-ten-Noode.

The Leopold Quarter traditionally encompassed the area immediately south of the Small Ring (Brussels' inner ring road), between the Namur Gate and the Leuven Gate. Nowadays, it lies roughly between the ring road, Leopold Park, the Rue Joseph II/Jozef II-Straat, and the Rue du Trône/Troonstraat. The district was created in 1837, soon after Belgian independence, as a prestigious residential area for the elite of the new Belgian capital, and was named after King Leopold I. It remained the most prestigious residential address in the capital until the early 20th century when many of its former residents began to relocate to the city's newly developing suburbs. Starting at that time, but accelerating rapidly only after the 1950s, it increasingly became a business/institutional area and is now dominated by the EU's facilities.

Arts-Loi (French, pronounced [aʁ lwa]) or Kunst-Wet (Dutch, pronounced [kʏnst ʋɛt]) is a Brussels Metro station on lines 1, 2, 5 and 6. It is located in the City of Brussels, Belgium, under the intersection of the Rue de la Loi/Wetstraat (lit. 'Law Street') and the Avenue des Arts/Kunstlaan (lit. 'Art Avenue'), after which it is named, the latter street being part of the Small Ring (Brussels' inner ring road).

The station's lower level opened on 17 December 1969, under the name Arts/Kunst, as a premetro (underground tram) station on the tram line between De Brouckère and Schuman. Its name was changed to its current form in 1971. This station was upgraded to full metro status on 20 September 1976, serving former east–west line 1 (further split in 1982 into former lines 1A and 1B). The station was extended on 2 October 1988 with the opening of the line 2 station, located on the upper level. Then, following the reorganisation of the Brussels Metro on 4 April 2009, it is served by lines 1, 2, 5 and 6.

Yser (French, pronounced [izɛʁ]) or IJzer (Dutch, pronounced [ˈɛizər] ) is a Brussels Metro station on the northern segment of lines 2 and 6. It is located under the Small Ring (Brussels' inner ring road), between the Place de l'Yser/IJzerplein and the Porte d'Anvers/Antwerpsepoort, in the City of Brussels, Belgium. The station takes its name from that aboveground square, itself named after the river Yser.

The metro station opened on 2 October 1988 as part of the Rogier–Simonis extension of line 2, the same year that line was converted from premetro (underground tram) to heavy metro. Then, following the reorganisation of the Brussels Metro on 4 April 2009, it now lies on the joint section of lines 2 and 6.

Porte de Hal (French, pronounced [pɔʁt də al]) or Hallepoort (Dutch, pronounced [ˈɦɑləˌpoːrt]) is a rapid transit station in Brussels, Belgium, consisting of both a metro station (on the southern segment of lines 2 and 6) and a premetro (underground tram) station (serving lines 4 and 10 on the North–South Axis between Brussels-North railway station and Albert premetro station). The station is located in the municipality of Saint-Gilles, south of the City of Brussels, under the Small Ring (Brussels' inner ring road) and next to the 14th-century Halle Gate, after which it is named. It is one metro stop away or about ten minutes' walk from Brussels-South railway station.

The metro station opened on 2 October 1988 as part of the Louise/Louiza–Gare du Midi/Zuidstation extension of line 2 from Simonis. Line 2 has since been extended beyond Gare du Midi to Clemenceau in 1993, Delacroix in 2006, and Gare de l'Ouest/Weststation in 2009. Since 3 December 1993, the station has also accommodated North–South Axis premetro services at separate platforms (the metro operates one level below the premetro lines). Then, following the reorganisation of the Brussels Metro on 4 April 2009, it is served by lines 2, 3, 4 and 6. Line 3 was disbanded in 2024 and replaced by the new line 10.

The Fortifications of Brussels (French: Fortifications de Bruxelles; Dutch: Vestingwerken van Brussel) refers to the medieval city walls that surrounded Brussels, Belgium, built primarily to defend the city but also for administrative reasons. There were two stages of fortifications of Brussels: the first walls, built in the early 13th century, and the second walls, built in the late 14th century and later upgraded. In the 19th century, the second walls were torn down and replaced with the Small Ring, a series of boulevards bounding the historical city centre. Nowadays, only a few sections of each walls remain, most notably the Halle Gate.

Rogier (French pronunciation: [ʁɔʒje]) is a rapid transit station in Brussels, Belgium, consisting of both a metro station (on the northern segment of lines 2 and 6) and a premetro (underground tram) station (serving lines 4 and 10 on the North–South Axis between Brussels-North railway station and Albert premetro station). It is located under the Small Ring (Brussels' inner ring road) at the Place Charles Rogier/Karel Rogierplein in the municipality of the Saint-Josse-ten-Noode, north of the City of Brussels. The station takes its name from that aboveground square, itself named after Charles Rogier, Belgium's 13th Prime Minister.

The station on the Small Ring opened on 18 August 1974 as a premetro station, and on 4 October 1976, a second premetro station on the North–South Axis was opened under the Small Ring station. The first premetro station became a heavy metro station, serving line 2, when this line under the Small Ring was converted on 2 October 1988. Then, following the reorganisation of the Brussels Metro on 4 April 2009, it now lies on the joint section of lines 2 and 6.