Pyrenees

Long ago, seas covered this land and left layers of mud and sand.

Then two huge pieces of Earth's crust pushed together. The rock folded and rose up into mountains.

The Pyrenees National Park tells the story in steps. In the Secondary era, seas spread over the worn-down remains of a much older mountain chain and laid down sediment for tens of millions of years.

At the start of the Tertiary era, the Iberian plate and the European plate collided. The rocks were pushed, moved and changed by heat and huge pressure. That is why the middle of the range is mostly granite and gneiss, while limestone and sandstone are common along its northern and southern edges.

In the park's account, Secondary-era seas of varying depth settled over the deeply eroded remains of the much larger Hercynian chain, depositing sediment for tens of millions of years. At the start of the Tertiary, the collision of the Iberian and European plates reworked these materials, displacing them and transforming them through heat and intense compression, which gives the range its great complexity.

The core is mainly plutonic (granite) and metamorphic (gneiss) rock, with sedimentary rocks (limestone and sandstone) dominant on the northern and southern margins. The folding also produced a volcano, the Pic du Midi d'Ossau. Walking up the valleys, one crosses rocks that record each major stage of the range's formation.

Later, glaciers moved down the mountains. They carved wide valleys.

Rivers also cut very deep canyons into the rock.

Glaciers came relatively late in the long history of the range. Their erosion shaped today's landscape and carved the big valleys that run north to south through the French Pyrenees.

Around Mont Perdu, a limestone massif on the border between France and Spain, UNESCO protects two of Europe's largest and deepest canyons on the Spanish side and three huge cirques, bowl-shaped walls of rock, on the steeper French side. The northern slopes have a damp climate shaped by the ocean, while the southern slopes are drier.

Glacial erosion, relatively recent compared with the range's history, shaped the present relief and created the large north-south valleys of the French Pyrenees, the park notes.

UNESCO's Pyrénées - Mont Perdu (inscribed 1997, extended in 1999 mainly for cultural criteria) covers 30,639 ha around a calcareous massif. It includes deeply incised canyons on the Spanish side and spectacular cirque walls on the more abrupt French slopes. UNESCO gives Mont Perdu's height as 3,352 m in its summary and 3,348 m in its statement of value. The northern slopes have a humid maritime climate, the southern slopes a drier Mediterranean one.

Wild animals called isards live on the mountain slopes. Marmots live there too.

Big birds called vultures glide in the sky.

The Pyrenees National Park is a refuge for many animals. It has large populations of isards, and colonies of marmots that were successfully brought back.

Big birds of prey soar overhead: bearded vultures, griffon vultures, Egyptian vultures and golden eagles. The park is also home to the capercaillie, the shy Pyrenean desman and the Pyrenean bear. Most numerous of all are the invertebrates; about forty kinds live nowhere else.

The park describes an exceptional diversity of fauna, preserved by its range of habitats and conditions, with many vertebrates protected nationally. It highlights large populations of isards, successfully reintroduced marmot colonies, and large raptors including the bearded vulture, griffon vulture, Egyptian vulture and golden eagle, as well as the capercaillie, the discreet Pyrenean desman, which the park calls a prime example of the natural heritage in its care, and the Pyrenean bear.

Invertebrates are the most numerous animals, and around forty species are endemic. UNESCO adds that the Mont Perdu area combines meadows, lakes, caves and forests and is one of Europe's most important mountain protected areas for its geology, scenery, fauna and flora.

In the national park, dogs stay at home, and everyone takes their trash back down.

Animals, plants and rocks belong to the mountains, so visitors leave them there.

The Pyrenees National Park asks visitors to prepare their outing well and to adapt to the mountain environment. In the park's core zone, dogs are not allowed, even on a leash. Visitors should bring bags to carry their trash back down, keep noise down, and leave animals, plants, minerals and fossils where they are, because they belong to the landscape.

Hunting is not allowed there: all the animals are protected.

The park's rules, shown by pictograms at trailheads, apply in its core zone, whose limits are marked on the ground by a red isard head on a white background. Dogs are not admitted, even on a leash; camping is not allowed, though regulated bivouacs are permitted more than an hour's walk from a road access, between 7 p.m. and 9 a.m.; no noise or disturbance; visitors carry their waste back down; animals, plants, minerals and fossils stay in place; hunting and weapons are banned, as all animals are protected.

The park also stresses preparing each hike carefully and adapting one's behavior to the environment.