2 Best Sights in Trier, The Rhineland

The oldest Christian church north of the Alps, the Dom was commissioned by Emperor Constantine in AD 330 and built on the site of the torn-down Palace of St. Helen, his mother. While the church burned down in 336, a second, even larger one was built soon after. Parts of the foundations of this third building can be seen in the east end of the present structure (begun in about 1035).

The cathedral you see today is a weighty and sturdy edifice with small round-head windows, rough stonework, and asymmetrical towers, as much a fortress as a church. Inside, Gothic styles predominate—the result of remodeling in the 13th century—although there are also many baroque tombs, altars, and confessionals. The highlight of the Schatzkammer (Cathedral Treasury) is the 10th-century Andreas Tragaltar (St. Andrew's Portable Altar), constructed of oak and covered with gold leaf, enamel, and ivory by local craftsmen. It's a reliquary for the soles of St. Andrew's sandals, as signaled by the gilded, life-size foot on the top of the altar.

An impressive reminder of Trier's Roman past, this edifice, now the city's major Protestant church, was built by the emperor Constantine around AD 310 as the imperial throne room of the palace. At 239 feet long, 93 feet wide, and 108 feet high, it demonstrates the astounding ambition of its Roman builders and the sophistication of their building techniques. The basilica is one of the two largest Roman interiors in existence (the other is the Pantheon in Rome). Look up at the deeply coffered ceiling; more than any other part of the building, it conveys the opulence of the original structure. An ornate rococo garden now separates the basilica from the Landesmuseum.