Boulogne-sur-Mer is a maritime city located on the Channel, near the Opal coast. The citadel of Boulogne-sur-Mer is built on a former Roman camp set up by Julius Caesar. The enormous dome of the basilica of Our Lady dominates the old city of Boulogne-sur-Mer.
On the last Sunday in August, a large procession is held to pay tribute to the men lost at sea, between the Chapel of the Seamen's Calvary and the Cathedral. Boulogne-sur-Mer is also the home of Nausicaä, the National Maritime Centre. The aquariums and exhibitions are aimed at helping the general public learn more about the sea and love it.