Cherbourg

– or rather, Cherbourg-Octeville, since the Commune of Cherbourg has now paired up with the Commune of Octeville to form a new, single commune. There are still two more in the agglomeration, one already twinned, so perhaps in future years we'll have to call the place Cherbourg-Octeville-Tourlaville-Équeurdreville-Hainneville.
Of course, nobody except the five mayors has ever called the place anything but Cherbourg.

Cherbourg has the biggest artificial harbour in Europe, and many centuries were spent (and many lives lost) in building it. It was designed to be a naval base which would dominate the English Channel, but the French Navy was never really up to the job. It is still home to much of that navy, and the vast Arsenal is the town's principal employer.

Cherbourg was also one of the two main French transatlantic ports, and the original terminal building is now a splendid maritime museum, complete with various ships and, of all things, a Russian submarine. Most of the rest of the port was destroyed by retreating Germans in 1944, but the Fort du Roule, on a clifftop above the town, still offers panoramic views and a Resistance museum. Cross-channel ferries, cruise ships and fishing boats now form the shrunken remnant of a hopeful past.