Here are a few suggestions for your next trip from Słupsk

In 4 hours, you can reach Posen.

In 5 hours, you can reach Warschau.

In 6 hours, you can reach Berlin, Łódź, Breslau.

In 7 hours, you can reach Krakau.

In 8 hours, you can reach Hamburg.

In 9 hours, you can reach Ostrava.

In 10+ hours, you can reach Paris, Budapest, Wien, Stockholm, Prag, Kopenhagen, Brüssel, Amsterdam, Vilnius, Bratislava...