Gisacum was a Gallo-Roman religious sanctuary near the settlement of Mediolanum Aulercorum

Mediolanum Aulercorum

Mediolanum Aulercorum was a Roman town of Northern Gaul, attested in the 4th century AD. The name means "the central town of the Aulerci", the tribe that then inhabited the area; Mediolanum was a small regional center of Normandy, then in the Roman province of Lugdunensis. The name of the modern...

 (Évreux

Évreux

Évreux is a commune in the Eure department, of which it is the capital, in Haute Normandie in northern France.-History:In late Antiquity, the town, attested in the fourth century CE, was named Mediolanum Aulercorum, "the central town of the Aulerci", the Gallic tribe then inhabiting the area...

) in the territory of the Eburovices

Eburovices

The Eburovices, or Eburovici, were a Gallic tribe, a branch of the Aulerci. They are mentioned by Julius Caesar with the Lexovii. Pliny speaks of the Aulerci, qui cognominantur Eburovices, et qui Cenomani. Ptolemy makes the extend from the Ligeris to the Sequana , which is not true...

 in northern Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

 (now Normandy

Normandy

Normandy is a geographical region corresponding to the former Duchy of Normandy. It is in France.The continental territory covers 30,627 km² and forms the preponderant part of Normandy and roughly 5% of the territory of France. It is divided for administrative purposes into two régions:...

). The site lies within the territory of the commune

Communes of France

The commune is the lowest level of administrative division in the French Republic. French communes are roughly equivalent to incorporated municipalities or villages in the United States or Gemeinden in Germany...

 of Le Vieil-Évreux

Le Vieil-Évreux

Le Vieil-Évreux is a commune in the Eure department and Haute-Normandie region of France.It is the site of the Gallo-Roman religious sanctuary Gisacum.-Population:-References:*...

("Old Évreux").

In the 1st century CE a vast sanctuary was laid out, about 6 km southeast of Mediolanum Aulercorum, on an all-but-unique plan: monumental public structures isolated at the center were surrounded by a vast empty space, with the urban habitations around a hexagonal periphery, 5.6 km in circumference, enclosing an area of some 2.5 km².

Gisacum has been excavated with increasing care since the early 19th century. The recent campaigns began in 1996.