The Basilica of Sant'Eufemia, completed around 579 by the Patriarch Elias, is the centrepiece of the old town and one of the finest early Christian buildings in northern Italy. The plan is a classic three-aisled basilica with reused Roman columns supporting round arches, and the mosaic pavement covers most of the floor — geometric patterns, inscriptions naming the families who paid for each panel, and birds and fish in a few of the medallions.
The campanile next to the church, with a copper-clad spire and an angel weathervane named "the Anzolo," is the icon of Grado. A small museum (the Lapidario) in the adjoining baptistery preserves Roman and early Christian fragments. The basilica is usually open through the day except during services.