Here are a few suggestions for your next trip from Blankenberg(Sieg)

In 2 hours, you can reach Köln, Düsseldorf, Frankfurt am Main, Liège, Essen, Dortmund.

In 3 hours, you can reach Brussels, Utrecht, Stuttgart, Anderlecht, Eindhoven, Strasbourg, Schaerbeek, Leuven, Nijmegen, Molenbeek-Saint-Jean...

In 4 hours, you can reach Amsterdam, Rotterdam, Antwerpen, Gent, The Hague, Basel, Charleroi, Tilburg, Brugge, Almere Stad...