The remains of the Armorican Massif
Brittany rests on a two-billion-year-old bedrock, the Armorican Massif. Shaped by uplift, folding, volcanism and sedimentary deposits, this mountain range, at times Himalayan in scale, at other times submerged under the sea, has been largely eroded over time.
The millennia have sculpted a gently undulating relief, interspersed here and there with deep valleys. To the west, two lines of rocky ridges have resisted erosion: the Monts d'Arrée to the north, and the Montagnes Noires to the south. The former are home to the region's highest peaks, which are all within a few centimetres of each other: Roc'h Ruz, Roc'h Trévézel, Roc'h Trédudon and Ménez Kador are all around 385 metres in altitude. Not far away, Mont-Saint-Michel in Brasparts titillates these peaks at 381 metres. At 330 metres, the Ménez Hom, at the entrance to the Crozon peninsula, offers one of the region's most spectacular panoramas.
The Armorican Massif is also characterized by its geological diversity: sandstone formed by successive deposits of sand, calcareous falun from shell debris, friable clay kaolins, gneisses, slates, schists, micaschists... And let's not forget the emblematic and omnipresent granite, with its many coloured variations: grey, blond, blue or the famous pink granite, which has given its name to one of the most beautiful stretches of coastline.
Between Ploumanac'h and Trébeurden, the poetic chaos of the Pink Granite Coast was born some 300 million years ago, when magma rose from the depths of the Earth and piled up in underground pockets deep in the Armorican Massif. It cooled very slowly, giving rise to this coarse-grained granite, pinkened by feldspar crystals. Erosion eventually exposed these soft, rounded rocks, sculpted by water and wind. In Ploumanac'h, they have taken on particularly picturesque shapes, while Île Renote, in Trégastel, concentrates blocks of colossal size. It's worth noting that this young granite rubs shoulders with two-billion-year-old gneiss, the oldest rocks in France, notably visible at the Pointe de Bihit in Trébeurden.
The Armor, a coastline with many faces
Brittany is a peninsula surrounded by the English Channel and the Atlantic, with some 2,730 km of coastline, making it France's longest coastline. The rugged beauty of the rocky landscapes at the end of the world, exposed to the winds and raging waves, and the gentle Mediterranean charm of sheltered coves and turquoise waters. The scenery is often very similar.
Dunes, shores, mudflats, long sandy beaches, intimate coves, jagged coastlines, spectacular cliffs, vertiginous peaks... the landscape changes, on average, every kilometer! A walk along the famous "Sentier des douaniers" (customs path) is a must to appreciate this incredible diversity. Once used to prevent smuggling, the route criss-crosses almost the entire Brittany coast, with the exception of a few jealously guarded sections. With relatively little concrete, the Breton coastline is also punctuated by ports and anchorages, old fishing villages and family seaside resorts that have retained their Belle Epoque charm.
A changing coastline that the movement of the tides, particularly powerful in the north, constantly reinvents: seaside landscapes are never quite the same. The amplitude of the tides - the highest in Europe - can reach 14 meters in the Bay of Mont-Saint-Michel, and the sea withdraws for several kilometers in the Bay of Saint-Brieuc. This reveals vast foreshores, rocks and islets that are temporarily accessible...
Each stretch of coastline has forged its own character: the polders, salt meadows and vast expanses of sand of the Bay of Mont-Saint-Michel; the charming seaside resorts and verdant shores of the Emerald Coast; the cliffs of schist and pink sandstone bristling with moorland around Cape Fréhel and, opposite, those of Plouha, the highest in the region, sheer walls of gneiss and granite... The wild, jagged coasts of Trégor resemble those of north Finistère, dotted with a multitude of reefs and islets, lighthouses, white sand beaches and deep estuaries. The tip of Finistère, exposed to the elements, offers grandiose landscapes, such as the Pointe du Raz. The southern coastline, from Cornouaille to the mouth of the Vilaine, is more built-up and peaceful, with low pine-planted coasts, chic resorts and beautiful, sheltered sandy beaches... The Quiberon peninsula, with its wild coastline, cuts through this peacefulness. The Ria d'Etel and the Gulf of Morbihan, quiet inland seas dotted with islets, offer postcard-perfect views.
The Argoat mosaic
Less densely populated than the coastal belt, characterized by scattered settlements and predominantly agricultural land, inland Brittany is home to four main types of landscape: bocage, which makes up the bulk of the landscape, moorlands, forests and marshes.
L'Argoat, literally "the edge of the wood", no longer has many of these: the Armorican Massif, once covered in trees, has undergone extensive deforestation since the rise of agriculture in the Neolithic period. As a result, Brittany is now one of the least forested regions in France. The mythical Broceliande exists only in legend, although it is commonly associated with the Paimpont forest, the largest in the region. Forests larger than 10 km² can be counted on the fingers of one hand, but wooded areas are plentiful.
The largest forest in Brittany is linear: it is formed by the bocage. Man-made, with embankments, trees or hedges, sometimes with low walls, it protects crops from the vagaries of the climate (wind, sun and bad weather). It limits runoff and soil erosion. A refuge for biodiversity, it also serves as a wildlife corridor. The bocage was severely affected by the land consolidation of the 1960s, which resulted in the disappearance of hundreds of thousands of kilometers of bocage and the creation in some areas of vast fields carved out for intensive farming practices: this is the case, for example, around Loudéac and Pontivy, while the areas around Rostrenen and Fougères, the Monts d'Arrée and the Montagnes noires still boast dense bocage. Today, efforts are being made to reconstitute it.
Another emblematic landscape, moorland, is also becoming increasingly rare, as a result of agricultural modernization. Unlike coastal moorlands, which grow naturally, inland moorlands are the result of human clearing. These once communal areas were used for grazing and provided farmers with bedding, fertilizer and fuel. At the time, moorland covered 30% of the land area, compared with just 2% today. The largest remaining areas are found in the Monts d'Arrée, which are also home to peat bogs. They can also be found, scattered among fields and woods, in the Paimpont forest, the Lavaux moorlands... Other examples include the moors of Locarn, Liscuis and Ménez Hom.
Finally, the region also boasts a number of marshy areas, mainly on its south-eastern borders, where the topography is low and flat: Muzillac, Séné, the Pays de Redon...
A dense hydrographic network
The region is criss-crossed by numerous small coastal rivers, especially in the west. Fed by thousands of streams, these short, fast-flowing rivers rise in the hills of inland Brittany and flow into the English Channel or the Atlantic. They often emerge into wide, sometimes deeply incised estuaries, known as abers in Breton, which run deep into the hinterland and into which the tides flow far upstream. Examples include the Blavet, the Rance, the Jaudy and the famous fjord-like abers of north Finistère (Wrac'h, Ildut and Benoît).
To the east, the landscape is flatter and the Vilaine flows slowly for some 230 km. It is the longest river in the region, ahead of the Oust, Blavet and Aulne. The Canal de Nantes à Brest, built in the 19th century, joins several rivers to cross the whole of central Brittany, while the Canal d'Ille-et-Rance connects the English Channel with the Atlantic, via the Vilaine. Several dams form artificial lakes: the largest is Guerlédan, on the Blavet. Other examples include Lac de Jugon, on the Arguenon, and Lac de Brennilis, on the Yeun-Elez peat bogs in the Monts d'Arrée.
Unfortunately, Brittany's waterways suffer from a number of problems, and only a third were considered to be in good ecological condition by 2019. They suffer mainly from discharges from intensive agriculture: pesticide residues and excess nitrate, which is the source of the green tides affecting certain parts of the coastline.
The weather forecast: a rain of comments
It's an inexhaustible source of jokes, sayings and comments of varying degrees of benevolence. If Brittany's weather is the talk of the town, it's no doubt because it's constantly changing, imposing its mark on the landscape and everyday life.
It's rare for the sky to remain invariably blue or hopelessly grey. It's more likely to be the scene of a ballet of clouds, alternating between rainy spells and triumphant sunshine in the space of a few hours. "In Brittany, the weather is fine several times a day", and we can experience "the four seasons in one day", we like to say here.
Cradled by the Gulf Stream, Brittany enjoys a mild oceanic climate, characterized by summers that aren't too hot and winters that aren't too cold, warmed by westerly winds. As for rainfall, with the exception of Finistère, it's in line with the national average, far from the rainy reputation that sticks to Brittany's skin.
There are nuances according to zone: the coast is generally milder, while the interior is cooler and wetter. The Gulf of Morbihan gets plenty of sunshine, as does the Rennes basin, which has little rainfall. In the west, however, the modest relief acts as a barrier to clouds, resulting in heavy rainfall.
The region is regularly battered by storms. Less affected by heatwaves, it is not immune to climate change. The main risks are linked to coastal erosion, marine submersion and the fragility of water resources, which depend essentially on surface water, which is sensitive to drought.
