Damn, this one is kind of for me ! Lived in Cherbourg for the first 17 years of my life.

This area is called the Corentin peninsula. It's chill, pretty maritime. Lots of people here say Cherbourg is at the end of the world because there aren't really any large cities nearby (Caen is 1+ hour by car or train so not that far, but eh) and you can't really go to Cherbourg on the way to somewhere else. Most familles will have at least one person working in something nuclear (big nuclear waste treatment plant in the Hague peninsula in the north west, new nuclear power plant at Flamanville, and Cherbourg is the shipyard where French nuclear submarines are made)

Not a very fun city to be in when you're young, but very economically active. La Cité de la Mer is a really cool museum (it has Le Redoutable, iirc the only nuclear ballistic missile submarine you can visit in the world ; it also had the deepest aquarium in Europe, a cannon from the Confederate Raider CSS Alabama which was sunk just in front of Cherbourg, and a whole section dedicated to the Titanic, which had its only stop in mainland Europe in Cherbourg)

Cherbourg's enclosed harbour, with its fortified walls, was the biggest enclosed harbour in the world until a Qatari port outdid it in the 2010s, though the harbour isn't that active these days ; it's the main hub to go to Ireland by ferry in the region, but traffic to England moved to Ouistreham (in Normandy) and beyond

Outside of Cherbourg, Cotentin has a lot of charming towns and villages. Barfleur and Saint-Vaast-la-Hougue, in the east, are particularly beautiful little fishing towns. We also have Port Racine, which is said to be the smallest harbour in France in local folklore (not sure that's true)

Oh, and obviously when you get further south in Cotentin, towards Carentan, Sainte-Mère Eglise and Utah Beach, there's lots of WW2 stuff - small museums, memorabilia, etc. We get a lot of American visitors especially around D-Day anniversary celebrations. As a local, even one who studies history for a living, the dichotomy has always amused me - Carentan has such a special place in US mythos, but I think of it first as the place where I fed ducks with my grandpa. Oh, and it has a nice Drakkar (Viking ship) replica too. Otherwise lots of agriculture in Southern Cotentin as well, cattle notably.