Our recommendation for accommodation during GUADEC 2016 is the Achat Plaza Hotel which is also the place where sponsored participants are staying:

It is centrally located between Karlsruhe main station and the venue at KIT (OpenStreetMap). The venue is quite close so that you can easily walk the distance. The public transport stop (Rüppurrer Tor) is just in front of the hotel. Tram lines number 2 and 5, as well as trains S4 and S41 take you the two stops to the venue (Durlacher Tor / KIT Campus Süd). Tram lines 2, S1, S11, S4, S41are going from the train station to the hotel. See the public transport page for more information about transportation in Karlsruhe.

If you are looking for other options, check the following places:

Hotels and tram stops
Hotels and tram stops

 

Location of the different hotels marked as dark blue and a selection of important tram stops in grey. The venue is marked in green.