The sensitive natural area

A remarkable beech grove can be found on the outskirts of the château: a rare woodland in a coastal environment. Other tree species are also present on the site, such as elms, ashes and oaks. The Château du Guildo cove is home to salt marshes. This is a natural wetland located between fresh and salt water. It's a highly specific environment conducive to diversified vegetation, adapted to the salinity.

This area is home to the rarest plant in its natural state in Côtes d'Armor to be found here: marshmallow officinale. This perennial plant is cultivated as a medicinal, ornamental and vegetable plant. If this plant seems familiar, it's because its roots have been used in the composition of a popular soft, sweet confection: marshmallow. There are around 4-5 plants on the site, and maintaining them is an important objective. Unfortunately, the diversity of the cove's salt meadows has declined over the last 15-20 years, and some species have been unable to be preserved. This is the case for at least five remarkable plants (Trifolium fragiferum, Salicornia obscura, Oenanthe lachenalii, Plantago maritima, Puccinellie fasciculée).

Near the Pointe de la Pépinais, between the coastal rocks, lies a rare plant endemic to the Normandy-Breton Gulf: the Norman statice. An endemic plant is a plant species unique to a specific geographic region. It has recently been granted protected status, having only recently been discovered. It is a highly endangered plant in the site, with only 5 feet remaining in 2009.

The Dune de Vauvert is certainly the most fragile environment on the site. The state of conservation of the dune is a cause for concern. Natural erosion factors (wind and tides) and human frequentation (increased number of paths, trampling) are contributing to its deterioration.

There are two threatened plants on the Armorican red list: Pubescent oat (a rare grass throughout Brittany), which is very well represented on the site, and goat orchid, which is an uncommon orchid. The flowers of the latter have the particularity of smelling bad, a strong and unpleasant "goat smell". Only 10 plants were found on the site in 2009. Some of these plants had been picked by walkers before flowering, which had the effect of reducing the remaining numbers and sometimes even leading to the destruction of a species on the site. It is important not to pick wildflowers in preserved environments such as this.

A total of more than 14 remarkable plants still grow at Dune de Vauvert. But some have been destroyed, as in the case of the maritime blue thistle, a species protected in Brittany, which is no longer present on the site. Because of its beauty, this plant is likely to be picked to make dried bouquets. Dune erosion may also be a factor in its disappearance. We must therefore be careful not to touch any of the plants present here, as this is a very fragile natural area. A temporary diversion may be set up in this case. Please respect it and stay on the path.

The mouth of the Arguenon is home to a small colony of 4 to 5 adult harbor seals accompanied by their pups. They are regularly spotted basking on the banks. This carnivorous mammal can measure nearly 1.80 m and weigh up to 120 kg. Unsuspecting, they fear neither boats nor swimmers, but remain wild animals with unpredictable reactions. Human disturbance has a major impact on coastal seal populations. It is therefore important not to approach them closer than 300m to ensure their tranquillity.

More than 10 species of bat (chiroptera) have been identified in total on the Château du Guildo site. In Côtes-d'Armor there are 19 species present. Bats are the only flying mammals in Europe. On the Château du Guildo site, they take refuge in the remains or in hollow trees in the surrounding woods. A birthing colony has even been established here, which is quite exceptional. Among the remarkable bat species is the Alcathoe's Bat, a species discovered only in 2001 in Greece. So far, very little is known about it in Brittany. The European Barbastelle and the Great Rhinolophus are listed in the appendices to the Natura 2000 convention as being of particular interest. The Greater Rhinolophus is a bat with a wingspan of around 40 cm. It can live up to 30 years. In Brittany, it is estimated that 90% of populations have disappeared over the last 30 years. Despite this, the region is still home to almost 20% of national numbers.

The Arguenon river is 53.4 km long. It rises in the commune of Le Gouray in Côtes-d'Armor and flows into the sea in the commune of Créhen. The river is home to a number of major migratory fish species. One of these is the European eel. This fish can grow up to 1m50 in length. It is now considered a critically endangered species. This is also the case for the Grande Alose, another migratory fish that is highly endangered in France. The population of these species has been in steep decline for several decades, due to pollution, habitat loss and overfishing. Sea lampreys, also threatened in France, are present in the estuary. These are not fish, but agnathans. They represent the most primitive level of vertebrates and are characterized by the absence of an articulated jaw. Their mouth disc has teeth that enable them to attach themselves to various species of fish, for transport when they are young or for feeding when they are older. They can measure up to 1m in Brittany. The bottom of the mudflat, flooded at high tide, is home to worms (Nereis, Arénicoles), mollusks (Coques, Clams, Couteaux) and crustaceans in abundance, attracting numerous birds such as the Aigrette Garzette, the Huîtrier Pie, the Courlis, the Tadorne de Belon in summer and the Bernard Cravant in winter.

In front of the château, on the left bank of the Arguenon bay, some astonishing stones have led to the inclusion of a new practice in France's Inventory of Intangible Cultural Heritage, in the "ritual practices" section. Ringing stones" are unique in that they make a metallic sound when struck with another stone. The particular sound of these rocks comes from the fact that they contain more iron than an ordinary stone. They are scattered along the beach at Goule d'Enfer, near the GR34. As with many Breton stones, sounding stones are associated with a legend. Here, they refer to Gargantua, who spent part of his life in Brittany and left his mark. Legend has it that these stones are the result of indigestion suffered by Gargantua, who swallowed them and then vomited them up...