Original Rolex Site
The venue, now hosting a university, is where the first Rolex watches were made, at the beginning of the 20th century. While no official visit is available, you can explore the outside of the building and its surroundings, which include other, beautiful, former Rolex production facilities. It is all located in a lovely part of Bienne near the old town, which has a lot of nice lunch options.
Further reading on Made in Bienne: