Flying in:
The closest airport is Münster/Osnabrück (FMO); quite convenient (25 min by taxi, 40 min by bus), but with only few connections.
Dortmund (DTM) is not much further away (1h by train), but with even less connections.
Düsseldorf (DUS) has a lot of national and international flights; there are frequent train connections (1.5h, direct or 1 change) to Münster.
Köln/Bonn (CGN) also works, but is slightly further away than DUS.
Frankfurt (FRA) is a major hub; appr. 3.5h by train from Münster.
Amsterdam (AMS): Many flights. Appr. 4h by train. Or 5. Or 6.
By train:
Alight at Münster Hauptbahnhof (Hbf). From there it is 10 minutes
by cab to the department, or to your hotel. You can also take the bus (less than 20 minutes), or walk (a good 30 minutes).
Getting around:
Münster is very walkable. It’s also very bike-friendly; at the station or downtown you can rent a bicycle (from the Radstation).
And there are plenty of e-scooters.
Some hotels not too far from the institute:
Hotel International am Theater
Some hostels: