While the stunning ancient architecture is the city's strongest draw, travelers should view buildings like the baroque St. Paulin's Church and the Church of our Lady, Germany's oldest Gothic church. Behind the medieval façades of the Cathedral, visitors find architectural styles from the 4th through 18th centuries.

Trier's expansive Electoral Palace, built as a "wing" to the Basilika, is considered one of the finest examples of rococo style in Germany, and its baroque Palace Gardens are a peaceful green oasis in mid-city. Another popular baroque attraction is the Karl Marx Haus birthplace and museum.

Perhaps one of Trier's most charming areas is its former Cathedral City, a mostly intact medieval district. Within the former city-within-a-city, a warren of narrow alleys runs between medieval houses. Much of the old wall still stands, if at somewhat precarious angles.

Despite the concentration of historic structures, visitors to Trier should not expect a mostly intact Old City on par with Regensburg or Heidelberg. After Allied bombing destroyed 40 percent of the city, Trier didn't follow the path of cities like Düsseldorf that built sparkling, modern cities atop the rubble. Nor did it follow the path of cities like Münster that re-built based on medieval plans. Instead, Trier faced a unique challenge and a pragmatic balancing act.

With most of the ancient city built over through the centuries and so many buildings destroyed during the bombing, Trier was forced to choose between excavating ancient buildings and constructing new ones. Although many tired, boxy department stores from the 1940s and 1950s stand in the shadows of the city's ancient monuments, the city frequently chose to excavate, a product of historic pride and hopes for the burgeoning tourist industry. The gamble has paid off, and tourism and wine are now the city's top two industries.

In 1987, UNESCO named Trier a World Heritage Site. In that same year, construction workers building an underground parking garage found the Forum Baths, today one of the city's popular attractions. "Every time someone puts a shovel in the ground, they find a piece of ancient Trier", one guide said, with little exaggeration. The moment a bulldozer unearths even a fragment of ancient wall, historical preservation laws require that construction stop and archeologists be called in.

Still, much of the ancient city, like the extensive temple district and the 80,000-seat Roman Circus, remains hidden and only partially charted. Although some guidebooks suggest ways to "see Trier in one day" or even one hour, the city deserves a two-day stay. With interior visits, it takes nearly a full day just to explore the attractions around the pedestrian district.

Several key attractions like the Barbara Baths, Roman Bridge and Amphitheater require a short walk or drive outside the central district, although still within the walls of the ancient city. Add to that a short boat ride or stroll along the Mosel and some quiet lunchtime moments at a wine bistro, and two days fill quickly.

Try to fit in a visit to the Rheinisches Landesmuseum, an outstanding archaeological museum with German's most extensive Roman collection. Some outstanding treasures include a giant mosaic of a Roman chariot driver, a grouping of magnificent glass artifacts, one of the world's largest collections of Roman coins, and a courtyard with building stones, columns and sarcophagi.