For an entrance fee of CHF24 (CHF15 with the Museums Card, free for under 25s with an Ausweis), it is possible to visit many museums in the area between 1800 and 0200. Many of the museums will be holding special events throughout the evening.  Free transport between different locations is provided.

Please see http://www.museumsnacht.ch/en/programm/index.php (most of the information is in German) for more information.