La Chaux-de-Fonds is a Swiss city in the canton of Neuchâtel. It is located in the Jura Mountains at an altitude of 992 metres, a few kilometres south of the French border. After Geneva, Lausanne, Biel/Bienne, and Fribourg, it is the fifth-largest city in the Romandie, the French-speaking part of the country, with a population of 36,915.