Bonn has good rail connections to major German and European cities. Three international airports are within easy reach.
Koln/Bonn Airport (CGN) is just 20 km north, connected by local bus in about 30 minutes. Dusseldorf Airport (DUS) is 70 km north -- take mainline rail to Dusseldorf Hauptbahnhof, then suburban rail to the airport (about 1 hour 10 minutes total). Frankfurt Airport (FRA) is 150 km southeast with direct mainline trains taking around 1 hour 40 minutes.
Bonn's Hauptbahnhof sits in the city centre with frequent ICE and regional trains to Cologne (20 minutes), Koblenz, and beyond.