The LibreOffice conference venue will be located at the main building of the University of Bern. Until the start of the semester on 15 September 2014 the building is mostly empty and thus available for LibreOffice conference.
The university is right on top of the Central Station (Hauptbahnhof). You can either use the elevator to "Grosse Schanze" or walk up "Schanzenstrasse" until you reach the "Parkterrasse" where you have a nice view over the city.
The address of the main venue is:
University of Bern
3012 Bern, Switzerland
Phone: +41 31 631 81 11
We made a map showing the three locations (main venue, location of the hack night and location of the social event).
The red pin shows the location of the main venue.
You can find the map here: http://umap.osm.ch/en/map/libreoffice-conference-2014-bern_44#16/46.9513/7.4369