Read: The German road less travelled from Frommer's Travel Guide
Celebrating its 51st birthday this year is the Burgenstrasse (Castle Road), an innovation brought to the public by lovers of medieval castles, who were convinced that the fortifications and scenery of southwestern Germany were as impressive as the better-known counterparts of the country's Romantic Road, farther to the east and north. The route has been extended, from Mannheim on the west to Prague in the east, with the most important stops -- Heidelberg, Heilbronn, Rothenburg ob der Tauber, Nuremberg, Bayreuth and Karlovy Vary -- lying in between. All in all, it's about 1,000 kilometers (620 miles) of scenic touring, and, except for the peak months of July and August, far less crowded than the more popular Romantic Road.
There are altogether more than 70 castles and similar stately homes on the road that passes, along the Neckar River Valley in and around charming towns and villages, most with an impressive fortification perched above. One of the best reasons for driving the Castle Road is the repeating opportunity to stay in remarkably comfortable castle hotels overnight, or, if pressed for time, to visit them for lunch or dinner.
An early American visitor to the Castle Road was Mark Twain, who hiked from Heidelberg to Heilbronn, stopping off at several towns, including Bad Wimpfen, along the way. He later wrote of having a meal on "a raft that is gliding down the winding Neckar past green meadows and wooded hills, and slumbering villages, and craggy heights graced with crumbling towers and battlements." (The locals assure me that although Twain did write about a raft trip down the Neckar, the voyage "never happened".)
One caveat about the Castle Road, entrancing as it is: there were no signs in English on any exhibit in any castle I visited, whether there was a museum or not, so you'll have to rely on your guide for explanations most of the time. Only Guttenberg Castle had an English-language booklet about its history. In fact, the official site (www.german-castles-road.com) for the route is mostly in German, with only a few pages translated into English.