St. Goar/Rhine River

"We will be staying for 4 nights so wondering if there are nearby towns that might be worth exploring?" Umm... yeah. Drive north to Bonn. Cross the river. Drive south to Wiesbaden. Cross the river to Mainz. Drive north again to St. Goar. Stop at anything that interests you along the way... and there is a LOT along the way. Also consider taking a left turn at Koblenz along the Mosel and driving to Trier and back. And if that's not enought, drive up out of the valley on the west bank to Bad Neuenahr-Ahrweiler and the abbey of Maria Lach. I could go on and on, but you get the idea.

Rather than just getting in the car and setting out, and stopping based on your impressions from the driver's seat of your car, I'd suggest a more deliberate approach. Do some thoughtful research based on your own interests and on the experiences of millions of folks who have already explored this region.

And don't feel restricted to the Rhine and Mosel River valleys, even though most sights tend to be there. It's just possible that you'd be curious about the amazing collection of buildings in Bad Sobernheim known as the Rheinland-Pfälzisches Freilichtmuseum, or Germany's finest racetrack (Nurbürgring) or the Hinzert Concentration Camp memorial site, or the intact German WW II B-Werk bunker in Besseringen, or gem-town Idar-Oberstein, or nicely-preserved Limburg on the Lahn River.

This guide breaks the area down by region and though not exhaustive is pretty complete and would be a good start.

The Middle Rhine Valley is one of my favorites in Germany.

http://en.wikipedia.org/wiki/Middle_Rhine

We most enjoyed St. Goar most but also really liked Bacharach, Oberwesel and Boppard. The Mosel Valley is likewise especially scenic.

The best guide that I have found for both these river valleys is the Michelin Green Guide.

How can we get from St. goar to Cochem and Burg Eltz? Can we do this as a day trip.

"How can we get from St. goar to Cochem and Burg Eltz? Can we do this as a day trip."

Yes.

By train? On a typical weekday, take 9:33 train north to Koblenz, change trains for Moselkern (arrive 11:11.)
Walk to Burg Eltz: Bavaria Ben's helpful walking tips
15:11 train from Moselkern to Cochem (arr. 15:28)
19:59 or 20:58 train back to St. Goar via Koblenz (takes 1 hr., 20 min.)

TICKET: At St. Goar's station buy a VRM mini-group ticket (€21.80) to cover whoever "WE" means up to 5 persons. It's good all day long for all these trains.

VRM group ticket

Get more specific train info yourself for your specific travel date at the DB itinerary page.

Thanks, just what I needed!