Luxembourg town near Cochem Germany

It would require half a day alone for the round-trip transportation to Vianden. Nice place though.

Maybe you should consider the historic towns that are closer to Cochem.

Trier: Germany's oldest city and a former outpost of Ancient Rome.
Bernkastel: The half-timbered houses here are much more impressive altogether than Cochem's.

Luxembourg is not that big. If by public transport, Luxembourg City is only 2 hours by train, less by car. You go through Trier to get there, well worth a visit, more interesting than Luxembourg City, IMO, but then not in Luxembourg to fill that checkmark.

If you're driving, especially along the river in good weather, why not tick that box? It would take all day, though, for sure. If you're driving, why not stay somewhere a little further upriver? I recently stayed in Enkirch, near Traben-Trarbach. The only other visitors were German (and two Russian guys who hilariously tried to drive their camper van and boat trailer down our street, which we had trouble navigating in our subcompact). There are loads of towns along the river that are not full of tourists.

Thanks all!

Vianden is nice; there's a very popular restored castle and a tram up to a restaurant on another close hill top. It's a town with a number of places for caravan camping. But you'd spend most of a day driving there and back from Cochem.

If you follow the river it can take 3-4 hours to drive from Cochem to Bernkastle-Kues. I've never managed to drive from Cochem to Trier in a day along the river. There's always something to stop and see, and if the weather is warm traffic will be slow. You can get there faster, but the routes not so scenic.

If you want a scenic place off the main route I suggest taking a 1.5 hour drive south east to Meisenheim, a 1100 year old town with the wall remaining, lots of old buildings, a really nice, small, church, and a couple very good (Michelin) places to eat.