"I want to go to Châtelet les Halles." For direct translation, you may say, "Je veux aller à Châtelet - Les Halles." (as given by the other respondent). However, to avoid confusion that the place is indeed a train station (not a city or something else), it is better to say, "I want to go to the train station of Châtelet - Les Halles.", which is translated as, "Je veux aller à la gare de Châtelet - Les Halles". Nevertheless, I further suggest that you use the conditional mood to express a desire that you want to go there, i.e., "I would like to go to the train station of Châtelet les Halles.", which means, "Je voudrais aller à la gare de Châtelet - Les Halles". --- Good weekend. / Bonne fin de semaine. / 祝　週末愉快。

You can say "Je veux aller à Châtelet les Halles".