Bern is a wonderful city for activities. You find a great information on the Website of Bern, press the highlights:
Walking through the old town
Really very exciting to walk through the alleys of Bern and see the town.
Clock Tower (Zytglogge)
The Clock Tower (Zytglogge) was Bern’s first western city gate (1191 – 1256) and is now one of Bern’s most important sights.
Paul Klee Museum
Very modern museum of the great artist Paul Klee, fantastic food.
Bärengraben (Bear Park)
The armorial of Bern has the bear. Visitors to Bern can observe live bears right in the heart of the Swiss capital.
The small mountain in Bern is always a nice walk out of the City with an beautiful view.