Set where the Moselle River meets the Rhine, some 79 mi/127 km northwest of Frankfurt, Koblenz, Germany, offers an impressive waterfront and a number of graceful 17th- and 18th-century buildings.

The team at Byway, a flight-free travel company, recommends tourists choose a small city if they’re looking for a walkable destination. They love Koblenz in Germany, which sits 'in a super ...