Here are a few suggestions for your next trip from Koper

In 3 hours, you can reach Ljubljana, Rijeka.

In 4 hours, you can reach Kranj, Celje.

In 5 hours, you can reach Maribor.

In 6 hours, you can reach Zagreb, Graz.

In 7 hours, you can reach Milan.

In 8 hours, you can reach Rome, Turin.

In 9 hours, you can reach Vienna, Munich, Linz.

In 10+ hours, you can reach Berlin, Paris, Budapest, Warsaw, Stockholm, Prague, Brussels, Amsterdam, Bratislava, Zürich...