The Merovingian crypt contains a magnificent white marble sarcophagus in which are the remains of the founder of the abbey of Echternach. 11th century frescoes. The papal basilica, whose present design dates from the 11th and 13th centuries, was seriously damaged during the Battle of the Bulge, and it was rebuilt in Romanesque Revival style. The crypt dates from the Merovingian period and has magnificent frescoes. It houses a sumptuous white marble sarcophagus, containing the mortal remains of Saint Willibrord. Other sights are the St. Willibrord fountain and the Renaissance confessionals. Its surroundings are used for the Echternach International Festival.