Can I use my German visa to travel to other countries in Europe?
Yes, you can. Holders of a Schengen Visa (text on the visa reads: "valid for Schengen-Staaten"), a longterm national visa or a residence permit of a member state can stay up to 90 days (within half a year) in the entire Schengen area. The Schengen area consists of the following countries:
Germany, Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden and Switzerland.
The Schengen Visa has to be applied for at the foreign mission of the country which is the main destination (generally longest stay). The country of entry and departure is not the determining factor. The entry into and departure from the Schengen area can thus occur at any border crossing.