UN Roundabout

Rondo ONZ is a roundabout in Warsaw, located on the border of the Śródmieście and Wola districts. The roundabout is joined by the following streets: Aleja Jana Pawła II from the north and south, Świętokrzyska Street from the east and Prosta Street from the west. The roundabout is equipped with traffic lights, pedestrian crossings, bicycle crossings and an underground passage integrated with the Rondo ONZ metro station. Trams pass through the roundabout from three directions (except from the east).The history of the roundabout dates back to the 1960s. The first extension of Świętokrzyska Street took place in 1955, and on December 4, 1963, an extension of Kasprzaka Street (Prosta Street) was pierced, creating a four-way intersection. The roundabout was opened on October 5, 1965, and its name, given in October 1986, commemorates the United Nations. In 2015, the Rondo ONZ metro station was opened under the roundabout.In the vicinity of the roundabout there are important office buildings, such as the Ilmet, Rondo 1, Skysawa office buildings and several tenement houses from the pre-war period.

Until World War II, Świętokrzyska Street only reached Bagno Street. In 1955, it was extended to Juliana Marchlewskiego Street (currently Aleja Jana Pawła II).This intersection became four-way on December 4, 1963, when an extension of Kasprzaka Street – Prosta Street [3] was built to this point. This created one of the two important city east-west communication arteries (the other was the W-Z route). The artery was to become part of the planned bridge route with the Świętokrzyski Bridge (built over 30 years later).The roundabout was opened on October 5, 1965. The name, given in October 1986, commemorates the United Nations.In 2015, the Rondo ONZ station of the M2 line of the Warsaw metro was opened under the roundabout.There are also several famous office buildings at the roundabout, including RONDO 1
rondo1.pl Wikipedia
pl.wikipedia.org/wiki/Rondo_ONZ_w_Warszawie

In fact, it is now the city's most tightly packed center, perhaps even more so than the city center houses that served this function in many previous cities.