Le Locle is known as a center of Swiss watchmaking, even cited as the birthplace of the industry, with roots dating back to the 1600s. The municipality has been home to manufactures such as Mido, Zodiac, Tissot, Ulysse Nardin, Zenith, Montblanc, Certina as well as Universal Genève, before the latter company relocated to Geneva. The town's history in watchmaking is documented at one of the world's premier horological museums, the Musée d'Horlogerie du Locle, Monts Castle, located in a 19th-century country manor on a hill north of the city. Restored historic underground mills (grainmill, oilmill, sawmill) can be seen in a cave located about one kilometer west of the city center.
The Ancien Hôtel des Postes, Monts Castle and the Museum d’horlogerie, City Hall, the Immeuble, Moulins souterrains du Col-des-Roches (Cave mills in the Col des Roches), the Villa Favre-Jacot and Zenith SA are listed as Swiss heritage site of national significance. It is part of the UNESCO World Heritage Site: La Chaux-de-Fonds/Le Locle, Watchmaking Town Planning (since 2009) and the entire town of Le Locle is part of the Inventory of Swiss Heritage Sites.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.