Decumanus

In Roman urban planning, a decumanus was an east–west-oriented road in a Roman city or castrum (military camp). The main decumanus of a particular city was the decumanus maximus, or most often simply "the decumanus". In the rectangular street grid of the typical Roman city plan, the decumanus was crossed by the perpendicular cardo, a north–south street. In a military camp, the decumanus connected the Porta Praetoria (closest to the enemy) to the Porta Decumana (away from the enemy). In the center – called groma – of a city or castrum, the decumanus maximus crossed the perpendicular cardo maximus, the primary north–south road. The forum was normally located close to this intersection.