I would tell people who plan to visit La Défense to realise that the underground ticket when traveling from Paris since the Défense area despite its proximity to the Arc de Triomphe belongs to the Metro zone 3 which means that the ticket is more expensive than that of the zone 1 of Paris. Do not try to cheat the monitoring station there is tight control of passage, if you have paid the wrong amount there is a fine of 30 euros per person and you will not receive kind treatment. Thanks!
The CNIT (Centre National des Industries et Techniques) is a convention center and exhibition in the middle of La Défense business district in Paris. It was inaugurated by General Charles de Gaulle on 12 September 1958, the first large building in La Défense. The man that created it dreamed of having a big exhibition center for industry, as well as existing centers and palaces within Paris, which in the end, didn't qualify. Thus arose the CNIT. In 1988 he began a great work to empty everything inside the center, increasing the total to 200,000 square meters instead of the 100,000 previously offered. It was modernized in 1989, which changed its function to a convention center. The CNIT also features many shops and kiosks, with FNAC as the most famous. It also houses the Hilton, which was the successor of the Sofitel, and several bars and restaurants. Therefore the CNIT surely looks like a mall rather than a conference center. Anyone can enter and many people that work nearby use the center for enjoying their breaks and to work out.