Rostock has its own airport, altough the amount of air traffic is very small. Luckily, both Hamburg Airport and Berlin Brandenburg Airport are less than four hours away by train. From either of those cities, you can take ICE trains to get to Rostock.

Rostock’s central station is located at Konrad-Adenauer-Platz and can be easily reached from multiple major cities in Germany and Europe. The german train company, Deutsche Bahn, usually offers journeys during all times of the day. These are some of them:

Arrival via Hamburg:

ICE 1578 (Stralsund Hbf)
ICE 1576 (Rostock Hbf)
ICE 1074 (Greifswald Hbf)
RE 1 (Rostock Hbf)

Arrival via Berlin:

ICE 2174/72 (Rostock Hbf)
ICE 2178/2176 (Rostock Hbf)
RE 5 (Rostock Hbf)

Rostock is located at the Baltic Sea, just about 230km north of Berlin and 185km east of Hamburg.

It can be reached by car via several motorways (Autobahnen):

A 19: Berlin (A 10, A 24) - Wittstock - Rostock
A 20: Hamburg (A 1) - Lübeck - Rostock - Stettin (A 11)

and federal roads (Bundesstraßen):

B 103: Plau - Güstrow - Rostock
B 105: Lübeck - Wismar - Rostock - Stralsund
B 110: Insel Usedom - Anklam - Demmin – Rostock

or European roads (Europastraße):

B 103: Plau - Güstrow - Rostock
B 105: Lübeck - Wismar - Rostock - Stralsund
B 110: Insel Usedom - Anklam - Demmin - Rostock

Once you have arrived in Rostock you can travel by bus and tram, which are managed by Rostocker Straßenbahn AG (RSAG), or with the S-Bahn, which is managed by the Deutsche Bahn. Tickets are available via VVW-App by Verkehrsverbund Warnow, at most tram stations or from the bus driver.

You can find the current route maps here.