If you ever need to travel between Frankfurt and Cologne, try your best to let the train take the strain. And make sure you take the slow train.
The express manages the journey in just over 80 minutes. The slow train takes an hour longer but includes an extensive and scenic trip up the Rhine river valley.
If you sit on the right hand side of the train from Frankfurt or the left from Cologne, you will be rewarded with wonderful views of the many picturesque towns on this winding stretch of the Rhine.
Every few kilometres, ruined castles and churches perch strategically above the river while thick city walls, watchtowers and the odd midstream fort stand guard down in the valley.
This has to be one of the most scenic rail routes in Europe.