Here you can find all you need to know in order to travel around in Kassel in an environmentally friendly manner:

The KasselCard (as of 2013)

24 or 72 hours of free travel on buses, trams and railways in the area Kassel Plus (the town and surrounding area).
Discount for guided city tours on foot or by bus offered by Kassel Marketing GmbH.
Discounts for other sights, such as museums.
The KasselCard is available, for example, at the Tourist Information centres in the Wilhelmsstrasse (inner city pedestrian precinct) and at the Intercity railway station Kassel-Wilhelmshöhe.

Prices 2013:

9.00 € for 2 persons – valid for 24 hours

12.00 € for 2 persons – valid for 72 hours

Seeing Kassel by public transport (as of 2014)

If you only wish to travel occasionally by bus, tram or RegioTram, you can buy tickets for single or multiple journeys with Kassel’s public transport. The tickets are available from ticket machines on board the trams and RegioTrams, from the driver on buses, or at one of the many ticket agencies (shops or kiosks) in and around Kassel.
Before starting your journey, please make sure which tariff zones you are travelling in, so that you purchase the appropriate ticket.

You can find an overview of the currently valid fares (PDF, EN) on the Website of the Kasseler Verkehrs-Gesellschaft.

Please remember to validate (time stamp) the ticket each time immediately after entering the bus or tram at the machines provided.