A few kilometres down the Rhine from Bacharach and on the other side, is the small town of Kaub. Its main attraction is the Pfalzgrafenstein, a remarkable, vaguely boat-shaped "castle" in the middle of the river. I use the term "castle" a bit loosely, as it wasn't a feudal lord's residence, rather a customs office on the river, with Gutenfels in the background providing a wider watch. A tollgate, basically. Sidenote, if you find other photos of this place, you'll notice how low the Rhine is right now...
While Burg Gutenfels in the hills has been converted into a hotel, not unlike Burg Stahleck discussed last time, the Pfalzgrafenstein has been preserved, and is open as a museum on some days of the week, with a small ferry allowing visitors to get there. Beside that, a car ferry runs all day between the two banks of the Rhine, so I could easily cross to quickly walk around Kaub.
Like a lot of riverside towns and villages in the area, Kaub is a charming place with many old buildings. It provides a picturesque backdrop to all the traffic going by, boats and trains, and the Rechte Rheinstrecke, the railway line between Wiesbaden and Koblenz on the right-hand side of the Rhine, was seeing more trains than usual, as the section between Mainz and Bingen on the Linke Rheinstrecke was closed. Long-distance trains, like this international EuroCity service bound for Zürich, were (and at time of writing probably still are) diverted via Kaub.