Berlin is the capital and largest city of Germany. It´s recent political history has left its marks, for example with the remainders of the Wall that separated East from West. Nowadays it is a very vibrant international city with lots of young people, startups, fashion, restaurants and art.
Dresden is a nice city in former East-Germany. The royal buildings are among the most impressive buildings in Europe. The most prominent building in the city of Dresden is the Frauenkirche.
München is the 3rd largest city of Germany and a highlight to any visit. It is great to have a beer here, during or outside the "Oktober fest". If you can get tickets, you may want to see Bayern Munich, one of the top clubs in Europe. The Black Forest is nearby for relaxing...
Aachen is a nice city, with a cosy old town, at the border with The Netherlands and Belgium. It is home to the 1200 year old Dom/Cathedral (#1 on UNESCO heritage list, since 1978).
The Chiemsee (aka. the Bavarian Sea because of its size) is a lake in the province of Bayern.
Cologne (Köln) is mainly known for: the Dom (huge cathedral), the Eau de Cologne ("parfume"), Carnival and the location near the river Rhine. Locals may also add the beer and the football club...
Frankfurt am Main is a major city and hosts the largest airport of Germany. It is also a large financial centre and home to the European Bank.
Garmisch-Partenkirchen is an Alpine city on the border with Austria. The Zugspitze (highest mountain in Germany) is nearby. The city is known for great skiing including famous ski-jumping tournaments.