From the World Heritage inscription:
Founded in the 12th century on a hill site surrounded by the Aare River, Berne developed over the centuries in line with a an exceptionally coherent planning concept. The buildings in the Old City, dating from a variety of periods, include 15th-century arcades and 16th-century fountains. Most of the medieval town was restored in the 18th century but it has retained its original character.
Bern is what you think of when you think of a Swiss city. It was actually my favorite city in Switzerland and I found it much more enjoyable than Zurich or Basel. The old city retains many of the traditional part of a Swiss town including the former apartment of Albert Einstein. It doesn’t get the attention of Geneva or Zurich, but I would highly recommend visiting if you are going to be in Switzerland.
View my complete list of UNESCO World Heritage Sites.