Highlights

• Stand at a Roman gate built without mortar by an elite legion hand-picked to fight Germanic tribes on the Danube frontier.

• Step inside a plain stone chapel that conceals one of Bavaria's most overwhelming Rococo interiors, often described as a glimpse of heaven.

• Hear how Regensburg's merchants grew rich enough to host emperors in their homes and built sixty towers just to outshine each other.

• Cross a nine-hundred-year-old stone bridge tied to a legend about a pact with the devil — and spot the bend he supposedly left behind.

• Visit the room where Johannes Kepler died waiting to collect a salary the Holy Roman Empire never paid him.