I arrived from France by car via the Col des Roches pass, after having visited Besançon and the Royal Saltworks. Given the limited time I had and due to the Covid-19 crisis, I decided to skip any museums or other indoor exhibitions (apart from a short elevator ride in the Espacité building) and to take advantage of the sunny weather to focus on architecture and urban planning. Thus, all places described as follows had free entry.
I drove to La Chaux-de-Fonds first (in case you don't have a Swiss motorway vignette and plan to just see the two listed towns and return to France afterwards, you may want to avoid the 1,000 meters of motorway between the towns by exiting the A20 in Le Crêt du Locle). Parking is mostly free in both communities but requires a parking disc. I started my tour at Le Crématoire, a fine example of local Art Nouveau. It is not located within the core zone. After having seen the Cure catholique romaine du Sacré-Coeur, I followed the recommendation of several other WHS community members and took the elevator up to the top of the Espacité building for a bird's eye view of this planned city. After a short walk to the Grand Temple, I continued with the Villa Jeanneret-Perret, also known as Maison Blanche, one of Le Corbusier's earlier works but not included in the "Le Corbusier WHS" (he was born in La Chaux-de-Fonds as Charles-Edouard Jeanneret). I liked the fact that one was allowed to access the front yard and terrace even after closing time. Several other early Le Corbusier buildings, such as the chalet-style Villa Fallet, can be found in this uphill area. I finished with Villa Schwob, aka Villa Turque, the Usine électrique de La Chaux-de-Fonds and the Temple Saint-Jean.
Smaller and quieter Le Locle is home to manufacturers Tissot, Montblanc and Zenith. My personal highlights were the picturesque Hôtel-de-Ville with its monumental frescoes (photo) and the seat of Zenith SA.
The towns are no eye-catchers and are lacking top notch single sights. As mentioned in the beginning, these centers of Swiss watchmaking are rather interesting from an architectural and urban planning perspective. I don't regret my visit but would not have wanted to stay longer. So I sneaked back to France for an overnight stay in a nice rural gîte.