Due to its central location in Europe, a lot of big cities are within reasonable distance. You can reach the following World cities in less than 4 hrs by car
Amsterdam 3h
Brussels 1h30
London by Chunnel 3h30
Paris 3h30
And some other relatively big cities
Antwerp 1h30
Calais 1h
Köln 3h10
Lille 1h10
Rotterdam 2h30