The venues of the Kongresszentrum are operated by the Karlsruher Messe- und Kongress GmbH (KMK).
Starting 1985 only the building of the Stadthalle was called Kongresszentrum.
In 2008 the Stadthalle is called Stadthalle again and the group of venues in total is called Kongresszentrum, this is a bit confusing.
This place in the City map:
There is a underground car park at the Festplatz. The car park is called "Kongreßzentrum".
From the Hauptbahnhof take the city railway 2, S1, S11, S4, S41 to "Kongresszentrum".
The second stop is not directly connected to the main station: