A compact Old City and an extensive pedestrian zone make Regensburg perfect for walking. Early morning is the best time to start your exploration. The stores are dark and the streets are silent, except for the bells and chimes that echo from church to church. Overhead, one after another, windows turn bright and the city awakens. An occasional sleepy voice mixes with distant organ music from first Mass.

As day breaks, moisture from the Danube drifts across the city as a dawny mist and casts an impressionist veil across the pastel stucco of patrician homes. Finally, the sun grows stronger, and the city’s towers and spires push apart the clouds to reveal patches of blue sky. Soon, schoolchildren with canvas backpacks run slalom around half-wake office workers and swap greetings with merchants sweeping their storefronts clean.

With a day of walking ahead, the first stop should be the Haus Heuport for a fortifying breakfast. Like many restaurants in this university town of all-night bookworms and club-crawlers, the Haus Heuport serves breakfast all day. If it’s sunny, sit out front and people-watch in the plaza. Otherwise, enter the courtyard, climb a double flight of stone stairs and find a window table in the massive main dining room, formerly the ballroom in what was once former patrician castle. The view couldn’t be better: the west façade of St. Peter’s Cathedral.

St. Peter’s is built on the site of the former Romanesque cathedral and reveals how Gothic styles evolved from its construction dates of 1276 to 1525. The evolution of stained glass is more distinct; the mosaic style of the medieval windows excites the spirit with their rich colors and powerful images. The painted 19th-century glass seems flat and lifeless in comparison. Recognizing a dying art—and the impact of acid rain and car exhaust on limestone and green sandstone—the Bavarian Government created a cathedral stonemason school. During summer months, visitors can watch the stonecutters work in the cathedral garden.

Today’s visitors see the cathedral in a new light. Since the first stone was laid, smoke from stoves and fireplaces had coated the cathedral with dense black soot. In 1997, careful sandblasting revealed its true colors for the first time in centuries.

The former merchants’ district lies to the west of St. Peter’s. The cobble-stoned district contains tempting storefronts—an enticing mix of merchandise from antique to kitsch, from fashionable to obscure. A meandering walk passes two of the city’s most striking patrician castles: the 13th-century Kastenmayerhaus with its four-story tower, and the Goldener Turm, with its imposing golden tower and Renaissance courtyard.

The route leads quickly to the Altes Rathaus, a complex of buildings and courtyards. Construction started with a 13th century patrician castle and ended with the Baroque town hall finished in 1723. Special points of interest along organized tours of the Rathaus include one of the last original torture chambers in Europe and the Imperial Hall, where the Perpetual Diet—in many ways Germany’s first parliament—met for nearly 150 years.

A two-minute walk north crosses the 16th century Italianate Fish Market to the Danube and to the Steinerne Brücke (Stone Bridge), an architectural achievement as impressive today as when it was built in the early 12th century. Resting on 16 massive pillars, the bridge stretches more than 1,000 feet across the river. As the only river crossing within miles, the bridge played a central role in the city’s growth as a trade center. Today, it provides a panorama of the old city’s spires, towers and steep-sloped roofs—dominated, of course, by St. Peter’s.