Like Londinium, it will be a port at the mouth of a river.
It will also be a crossroad between Hispania, Britania and Narbon or Roman Provincia.
A Gaul tribe lives there: the Bituriges Vivisci.
There are many resources such as vines, wheat, fish, marble, clay, timber... and you should have no problem to get money quickly.
Open trade routes by the Atlantic Ocean. Careful, that sea is rough !
You may have the visit of our new enemy: the Visigoths, who'd like to establish themselves in this fertile area, too...