Dillingen is a Landkreis in Swabia, Bavaria, Germany. It is bounded by the districts of Donau-Ries, Augsburg and Günzburg, and by the state of Baden-Württemberg. In ancient times the Danube river was a border between the Roman Empire and the Germanic tribes north of the river. The Roman camp of Phoebiana was a bridgehead crossing the Danu…Dillingen is a Landkreis in Swabia, Bavaria, Germany. It is bounded by the districts of Donau-Ries, Augsburg and Günzburg, and by the state of Baden-Württemberg. In ancient times the Danube river was a border between the Roman Empire and the Germanic tribes north of the river. The Roman camp of Phoebiana was a bridgehead crossing the Danube. There was an Apollo temple being one of the largest buildings north of the Alps in that time.