The department includes the
Cotentin Peninsula down to the famous
Mont St Michel. Of the
Channel Islands, only
the island of Chausey forms part of the territory of the department. Manche borders the Normandy departments of
Calvados to the east and
Orne to the southeast.
Mayenne, a department of the
Pays de la Loire, is to the south-east, and
Ille-et-Vilaine in
Brittany is to the south-west and it shares maritime borders with
Bailiwick of Jersey and
Bailiwick of Guernsey of the
United Kingdom to the west. The
salient of this department is the longest in France. It is also the second longest in Europe, after
Odesa Oblast in
Ukraine. The region is lush and green with sandy beaches and remains oriented towards farming. The peninsula was originally joined as a single land mass to
Cornwall and
Dorset in England, meaning that the underlying
geological strata of both regions are very similar. However, there are substantial regional differences today in terms of flora and fauna, and farming practices have varied considerably between the United Kingdom and France. Flat marsh areas in the department attract many bird-watchers. The region in and around St Lô is also the equestrian capital of France, where the cooler climate compared to the south is ideal for breeding and training. France's first
EPR nuclear reactor is under construction at
Flamanville near
Cherbourg and is planned to start operations in late 2023.
Principal towns The most populous commune is
Cherbourg-en-Cotentin; and the prefecture
Saint-Lô is the second-most populous. As of 2023, there are six communes with more than 10,000 inhabitants:
Climate The climate is
oceanic with relatively mild winters in which temperatures go below zero only for a few days. Summer temperatures are usually around 20 °C, and can occasionally reach 35 °C in direct sunlight. Precipitation is heavy but varies greatly by region, from 700mm on the coast to 1300mm in the southern central area. Highly localised but not life-threatening flash flooding has been experienced during the last few springs. The west coast benefits from the influence of the
Gulf Stream and this has enabled the naturalization of Mediterranean and exotic plants such as mimosas, palms, and agaves. There is often a sea breeze on the coast, which combined with tides, contributes to rapid temperature changes in the course of a single day. Sea temperatures can be very pleasant for swimming between June and October. == Demographics ==