The RER B is one of the five lines in the RER subway system serving Paris, France.
The line runs from Robinson (B2) and Saint-Rémy-lès-Chevreuse (B4) to Aéroport Charles de Gaulle (B3) and Mitry-Claye (B5)
Line B was the product of the connection in 1977 of the Ligne de Sceaux terminus, Luxembourg, with the Gare du Nord via Châtelet - Les Halles. In 1988 St-Michel - Nôtre-Dame station between Luxembourg and Châtelet - Les Halles was opened to provide connection with RER C and Métro Line 10 at Cluny - La Sorbonne, a station which had been closed since the beginning of the second world war and was entirely renovated for the occasion.
RER B | RER B (Île-de-France) | Ligne B du RER d'Île-de-France