Oescus, or Palatiolon Palatiolum, (in Bulgarian Улпия Ескус, Ulpia Eskus) was an ancient town in Moesia, northwest of the modern Bulgarian city of Pleven, near the village of Gigen. It is a Daco-Moesian toponym. Ptolemy calls it a Triballian town, but it later became Roman. It was linked by a bridge over Danube with ancient city Sucidava (modern day Corabia - Romania) by Constantin the Great.