The Celtiberian city stood a few kilometres away on the opposite bank of the river, and was a military camp during the Sertorian War.

Livy recounts how the powerful and famous city of Ercávica, scared by the disasters suffered by neighbours, decided to open its doors to the Romans.

The Augustan period saw the transformation of Ercávica with the construction of sophisticated buildings such as a forum, basilica and temple(s), and the grant of status of municipium as shown by coins issued by its mint.

The square is rectangular, paved with large stone slabs surrounded by arcades, and on its southern side the basilica for judicial functions.

On the western side is a group of small houses or shops, open to the main road (cardo maximus) that ran from north to south.