Les Halles was Paris' central fresh food market. It last operated on 12 January 1973 and was replaced by an underground shopping centre and a park. The unpopular modernist development was demolished yet again in 2010, and replaced by the Westfield Forum des Halles, a modern shopping mall built largely underground and topped by an undulating 2.5 hectare canopy. The mall sees around 50 million visitors every year, making it the busiest in France as of 2019. It is directly connected to the massive RER and métro transit hub of Châtelet–Les Halles, Paris's busiest station.

The Réseau Express Régional, commonly abbreviated RER, is a hybrid commuter rail and rapid transit system serving Paris and its suburbs. It acts as a combined city-center underground rail system and suburbs-to-city-center commuter rail. In the city center, it acts as a faster counterpart of the Paris Métro, having fewer stops.