Les Halles is a station on line 4 of the Paris Métro in the 1st arrondissement.
The original station on 21 April 1908 as part of the first section of the line from Châtelet to Porte de Clignancourt to serve Les Halles (the old markets). The station was rebuilt in 1977 about ten metres further east to interchange with the new Châtelet - Les Halles RER station. This RER station is connected by underground corridors to the Métro station Châtelet, and Les Halles is therefore also connected with Châtelet. The Métro Line 4 is the only line that serves Les Halles, and in addition it also serves the Châtelet station.
The walking distance from (Line 4) at Les Halles to the far end of Châtelet (Line 7) is about 900 m. (But one would interchange between Line 4 and Line 7 at Châtelet instead.)
There's a big shopping chentre underground in the zone of Les Halles, composed of numerous floors, one of them serves as the Métro Station and the interchanger.