Here are a few suggestions for your next trip from Leiden Centraal

In 2 hours, you can reach Amsterdam, Rotterdam, The Hague, Utrecht, Almere Stad, Haarlem, Zaanstad, Brussels, Antwerpen, Anderlecht...

In 3 hours, you can reach Gent, Liège, Groningen, Düsseldorf, Essen, Lille, Leuven, Enschede, Mons.

In 4 hours, you can reach Paris, Charleroi.