For as much as 11€ you can go to Poland by train and visit Szczecin.
The city was founded in the 8th century by Slavic tribes. Between then and now it was ruled by various kings and nations. It was Danish, Swedish, Polish, was part of the Holy Roman Empire of the German nations and is now Polish again.
Szecin is located right at the Baltic Sea and has a huge seaport. Much of the city centre has been distroyed during WW2 but has been rebuilt to its original Art Nouveau style. Don’t get a shock though, social realism it quite prevalent.
So, if you are up a for a fresh fish sandwich at the sea, you can find tickets here
More info in English is available here
go there – have a fish