La Porte Noire, a Roman arch on the Rue de la Convention, leads you to the 12th-century Cathedrale Saint-Jean.
La Porte Noire is an arch made of limestone.
mnli hypothesis: La Porte Noire is an arch made of limestone. premise: La Porte Noire, a Roman arch on the Rue de la Convention, leads you to the 12th-century Cathedrale Saint-Jean.