Châtelet – Les Halles is the major commuter train hub in Paris. It is one of the largest underground stations in the world. Taken together with the Paris Métro stations Châtelet and Les Halles, to which it is directly connected, hosts 750,000 travellers per week day (including interchanges), 493,000 for the RER only. It is named after the Châtelet monument and the former market of Les Halles.