Estany de Sils

Permanent exhibition

1 Once upon a time...

The old lakes of La Selva

The deepest and little drained parts of La Selva plain have contained an extensive mosaic of lakes, lagoons and wetlands since historical times.

The lake of Sils was the largest of the Selva plain. Some records state it was some seven kilometres long and a kilometre and a half wide.

From prehistoric to relatively recent times humans have obtained products from the lake areas which were basic for survival: hunting, fishing and raw materials for basket-making, such as wicker, reeds and rushes.


Old maps show the large area of the lake of Sils, which was one of the biggest in Catalonia. These days the old lake reappears occasionally in periods of heavy rain.

An ancient human occupation

As in other parts of the plain of La Selva, remains of human occupation, dating from between 150,000 and 300,000 years old, have been found in this sheltered field on a peninsula which protrudes into the old lake of Sils.


Between the High Road

The Via Augusta Roman road seems to have divided in two when it arrived at the lake of Sils: one part passed by the Granota Hostal and went on towards the coast, approximately following the route of the present day N-II main road, while the other part headed inland.


Making use of ice

In the past the ice which accumulated in the lakes were used extensively. It was removed from the lake and kept in wells throughout the winter so that it could be used in the summer. This use of ice coincided with a climatically cold period from the 16th to 19th century, known as the “Little Ice Age.”


2 Myths, fears and legends

The lakes’ bad reputation

Malaria was a common illness of the inhabitants of lakeland areas until the beginning of the 20th century.

The lakes were considered sickly places because of the malaria. Until the discovery of infectious processes, medical knowledge was unable to understand that the illness was due to a micro-organism, Plasmodium, transmitted by the Anopheles mosquito.

The recurrance of illnesses made the terrified villagers look for supernatural protection. The worship spread to Saint Sebastian, Saint Roc and the Saint doctors (Saint Cosme and Saint Damian, the patron saints of Sils), considered protectors against all types of plagues.

The lake of Sils was known as the gateway to Hell. Legend has it that the devil landed here when he jumped from the top of Montseny following a bet with Saint Martin to see who could jump the furthest. An anonymous script from the 17th century, the legend of Pere Porter, explains the story of a poor man who was thought to still owe a debt that he had already paid, and to demonstrate his innocence travelled to Hell via the lake of Sils, where he met the notary responsable for the error. A story similar to that of The Divine Comedy where the members of influential social classes are criticised through Pere Porter finding all of them in Hell.

The culprits of the deserved bad reputation

The Anopheles mosquitoes which develop in stagnant water are the main transmitters of malaria. These days, this disease, which has practically been eradicated in Europe, continues to affect many people in tropical countries.


The Tossa Pilgrim

Since the end of the 15th century, on every 20th January, the Pilgrim walks from Tossa to Santa Coloma de Farners, passing through Sils, in order to fulfil a promise made to Saint Sebastian to free the town of Tossa from the plague. The worship to Saint Sebastian has been traditionally associated with the protection from epidemic illness.


Fear of the lakes

There have been many legends of pitiful souls and supernatural beings based around the lake. Many refer to the screams, brays and howls that ressound from the water at dusk. Without a doubt the calls of waterfowl and the evening mist have much to do with the origin of this magical universe.


3 A long history of drainage

A fight against the water

Attempts to drain the lake of Sils have been continuous since the middle ages, on many occasions only with limited success.

Chronology of the drainage


 First attempts at drainage promoted by the Viscount of Cabrera


 The lake resurges and much arable land remains under water


 Various initiatives for draining the lake


 The marquess of Aitona and the engineer Martí Mariscal sign a contract for draining the lake. The work was never carried out


The Duke of Medinaceli, the owner of the lake at the time, places boundary stones around the lake with the inscription “ESTAÑ MARC EN 1740”


The Duke of Medinaceli signs a new contract for draining the lake of Sils


Drainage works are carried out


Accounts by the traveller Francisco de Zamora infer the drainage attempts of 1767 were ineffective


The water refuses to leave 1400 vessanes (about 320 hectares) of land


The queen mother Maria Cristina stays at the Granota Hostal. The mayors of Sils, Maçanet de la Selva and Vidreres visit her and explain the need to drain the lake


Conversations begin between the Duke of Medinaceli, owner of the lake, and the tenants regarding drainage. An agreement is signed before the notary of Girona J. M. Salomó


The agricultural engineer J. Bayer directs the drainage works. The Sils drainage channel is built


One of the boundary stones placed by the Duke of Medinaceli in 1740.


Sèquia de Sils, central drainage channel of the old lake.


Wall built on the left bank of the Santa Coloma ephemeral stream to stop water returning to the lake of Sils.

The definitive draining of the lake of Sils was achieved by the construction of a central drainage channel, the present Sèquia de Sils which empties into the Santa Coloma ephemeral stream. Due to the slight gradient of the land, it was necessary to build a stone wall to stop water returning to the lake in periods of high rainfall.

Hygiene and land

The definitive draining of the lake of Sils was seen as beneficial by the leading hygienists of the 18th and 19th centuries who supported the drainage of lagoons in the fight against the plague. The need for new land for agriculture also spurred on the drainage of this and many other lakes.


Ariel image of part of the land gained from the old lake of Sils where the complex system of drainage can be seen in a landcape still dominated by meadows.

4 The last changes

From grass to poplar

Following the definitive draining of the old lake of Sils the land was divided into small plots for the farmers of the surrounding area.

The division of the land wasn’t for nothing, as the new owners were obliged to pay a tithe to the Dukes of Medinaceli, the old owners of the lake.

The farmers kept the drainage channels free of sediment using their own personal effort.

For many years the meadow was the main economic resource of the lake of Sils. The complicated drainage of the area, made farming difficult, but it produced good harvests of grass: a real treasure for the small farms and cattle breeders of the time.

The socio-economic changes of the last decades have led to the collapse of small farms. The meadows are no longer of economic interest and have either been abandoned or converted into fields of poplar trees. The tithes are no longer paid and nobody looks after the drainage system with any regularity. All this has meant a significant change to the landscape and the functioning of the natural systems of the area. The photographs of the last years are a real testimony to this important change.


The fragmentation of the land

The constuction of the A-7 motorway divided the land of the old lake of Sils in two. Subsequent increase and expansion of the surrounding road traffic and urban development of the area have led to isolation and fragmentation of this natural area.


A change in the concept for the uses of water

The dredging of the drainage channels using heavy machinery – instead of traditional methods of dredging – and the heavy pollution of the water have affected the natural systems of the lakes of Sils for a long time.


Mass extinctions

All the new interventions have provoked the disappearance of numerous species of flora and fauna from the aquatic environment, meadow environment and open areas in general. A mass extinction that the drainage of the lakes alone could not have produced.


Ferrets and water clover are some of the rare species which have disappeared from the lake in the last decades.


5 The natural values

A different humid area

The lake of Sils is a humid area with some characteristics which are unique in Catalonia.

A good part of this singularity is due to the relatively humid climate and the marked thermal inversion from the plain of La Selva.

Therefore, despite its proximity to the Mediterranean, the lake of Sils has sections of landscapes which are associated with colder and more humid places, mixed with typical Mediterranean vegetation in the drier, sheltered parts.

The diversity of environments favours the presence of a varied fauna. All in all, this makes the lake of Sils, despite its small size, important regarding the conservation of biodiversity.


Here is a small sample, in images, of the rich nature of the lake of Sils and the lands that surround it.

The migration of aquatic birds

Aquatic birds are probably the most seen and best known inhabitants of wetland areas. Every year millions of these birds make a long return journey from the north of Europe to warmer parts where they spend the winter. This is the time many of them stop at our lakes and marshes.


Voluntary invaders

Globalisation also leads to the colonisation of new territories by species transported by humans. Their presence often brings important alterations to the working of the natural systems. Around the lake of Sils, minks, American red crabs and Florida turtles have become regular, and problematic, guests.


6 Conserving the natural and cultural heritage

A new history for the lake of Sils.

The uses of the land and of the natural resources have changed throughout history according to the needs and desires of the people.

In olden times the lakes and marshes were valued for their direct resources: fishing, hunting, raw material for basket-making, etc. In more recent historical time the scarcity of land led to the drainage, often against the wishes of their feudal owners. In the last years the decline in traditional agriculture and cattle rearing and the expansion of urban areas has led to a growing degradation of the last lakes and marshes.

Today there is a global conscience regarding the need to conserve wetland areas. This situation, similar to the past drainage policies, is not exempt of conflict. Nevertheless, future generations can judge whether we have done well or not.

The lake of Sils has been legally protected since 1992 when the Pla d’Espai d’Interès Natural de Catalunya (PEIN) (the Area of Natural Interest of Catalonia Plan) was approved. In 1999 with the approval of the Pla Especial de Protecció de l’Estany de Sils, turons de Maçanet i riera de Santa Coloma, (a special protection plan for the lake of Sils, the hills of Maçanet and the ephemeral stream of Santa Coloma), measures ruling the preservation of the area were widened.

Cleaning the waters

One of the first jobs carried out at the lake of Sils was to improve the quality of the water. This was a priority because of the area’s status as wetlands, something which allowed Sils, Vidreres and Caldes de Malavella to have water treament works much earlier than other municipalities of similar population.


Cutting and maintaining the meadows

Some of the most characteristic landscapes of the lake of Sils, such as the meadow, are actually semi-natural systems which can only be maintained through traditional exploitation. The conservation of the lakes also implies the continuity of uses and customs compatible with the conservation of the natural environment which respresent a cultural trace we cannot afford to lose.


Leisure and education

Due to their exceptional biological richness, wetland areas have become attractive places for citizens who require, more and more, the need for direct contact with nature. For this reason they have become ideal places for environmental education. A new use for new social needs and new mentalities.


7 An integrated project to promote environmental education, leisure time and eco-tourism

Returning life to the lake

Following decades of big changes to the natural systems and landscape of the lake of Sils, it was finally agreed the need to preserve this place of unique natural and cultural values, beyond simply local interest, for future generations.

The aims of the project

Conserve a small example of the natural systems and landscape of the lake of Sils and its evolution through history.

Create conditions that conserve and improve the biological diversity of the area.

 Improve the quality of the water.

Make use of the area for environmental education, leisure and ecological tourism.

All these actions are initially carried out in an area of approximately 30 hectares, which corresponds to 10% of the protected area of the old lake of Sils. Its importance, however, lies in the fact that it is meant to be an experimental process to demonstrate a management model which in the long term, will guarantee the conservation of the whole area.

The actions

Recuperation of part of the original lagoon as a sample of the old lake to improve the habitat of the most threatened aquatic fauna and flora species and to improve the water quality by filtering through vegetation.

Recuperation of the bankside vegetation and research into new sustainable forest use as an alternative to the poplar plantations.

Recuperation of the traditional processes of meadow management typical of the area.

Provision of an information centre and creation of nature trails with information boards.

Production of a management plan and following up of the actions carried out.

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hometroncs                        paisatge

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With the heat the water level drops and it is only found in the drains and ditches, close to which ducks gather to renew their plummage, protected by the dense Carex sedges (locally known as balcallons), which complete their annual growth at this time of year. Bindweed and purple loosestrife flower among these grasses, while bee-eaters and swallows look for insects near the water and groups of waders gather in the muddy pools.

Bee-eater [Abellerol, Merops apiaster]

The Bee-eater is one of our most attractive birds due to its variety of colours. The name comes from its passion for eating bees and wasps, and because of this diet it migrates to Africa for the winter. Once breeding has finished, bee-eaters usually concentrate near to water. That’s why they are common at the lake in summer. As the rain disturbs them and because the majority of them migrate at the end of the summer, when heavy storms usually occur, they have become known in the county as “the birds of bad weather”.


Dragonfly [Espiadimonis, Aeshnidae]

The dragonfly is one of the few insects people actually appreciate. This could be due to its attractive colours and acrobatic flight. But, beware! Behind this beauty lies a relentless carnivor. The young live in the water and are capable of hunting down tadpoles and small fish. In summer they can be seen flying over any body of water.


Swallow [Oreneta comú, Hirundo rustica]

The Swallow is one of the most loved birds for many

people. In summer and before starting the migration to Africa, many swallows concentrate around the lakes where they find abundant food to build up reserves before their long journey.


Wood sandpiper [Valona, Tringa glareola]

When the water level drops there are many muddy pools used by waders - aquatic birds which look for their food in the mud or shallow water. There are many species of wader but one of the easiest to spot is the Wood Sandpiper. Many of these birds migrate south at the end of summer after breeding in the north of Europe during the short spring.


Badger [Teixó, Meles meles]

Despite being a rather large animal, the badger is discreet and nocturnal which makes it difficult to see. However it is more common than you would think and it is not difficult to see its footprints in the mud. It is a greedy animal which eats fruit, mushrooms, meat and generally everything it finds in front of it. It often comes down to the lake at night to look for worms, crabs, frogs and anything else it can catch.


Pond turtle [Tortuga d’estany, Emys orbicularis]

The pond turtle is one of the most emblematic animals of the lake of Sils and the area has one of the largest populations in Catalonia. It is a threatened species which, in recent years, has unfortunately suffered undesirable competition from an introduced species, the Florida turtle. When the weather is warm the turtles can be seen sunbathing on the water’s edge early in the morning, but when the sun is very strong they shelter in the vegetation or the water. In high summer they usually become more nocturnal.


Purple Loosestrife [Salicària, Lythrum salicaria]

The splendid purple loosestrife flowers among the Carex grasses in the months of June and July. The spiked purple flowers emerge from the green of the grasses and give a touch of colour to the summer landscape of the lake.


Sedge [Balcalló, Carex riparia]

In Sils the Carex sedges are known as balcallò and they grow in flooded places forming high (more than a metre), dense and inpenetrable grasslike areas. These sedges make up one of the most characteristic landscapes of the wetlands of Sils, mostly due to the large area they cover. In summer the balcallò reaches its maximum height, showing its brownish spikes. Frogs look for the cool shade in these grasses and the young chicks of aquatic birds like the Water Rail and Moorhen hide here.



Spring arrives at the lake of Sils with the blossoming of the grey willow. Later on, the meadow comes into bloom with lovely ochids and abundant clumps of the yellow flag iris. This is the best time to see the birds thanks to the abundance of water, where migratory waterfowl stop to rest and feed. The nesting of the ducks adds to this natural spectacle which at this time of year displays its maximum vitality.

European Tree Frog [Reineta, Hyla arborea]

Frogs and toads awake in spring following their winter hibernation. The European tree frog is one of the nicest examples despite being very difficult to see amongst the leaves of the reeds, irises and bullrushes which offer perfect camouflage. The voice, however of this little climbing frog is perfectly audible, especially on cloudy, humid days. For this reason, it is said that its song signals rain. Something not far from the truth.


Little Egret [Martinet blanc, Egretta garzetta]

With its perfect plummage, the Little Egret is found in shallow waters where, thanks to its long legs and sharp beak, it catches fish, frogs and small aquatic invertebrates.


Marsh Harrier [Arpella, Circus cyaneus]

The spring, during migration time, is the best time to see this beautiful bird of prey in Sils. The Marsh Harrier lives in wetland areas. The female, which is significantly bigger than the male, can be seen flying above the sedges and reeds looking for food, mainly small reptiles, amphibians, rodents and the young of other birds. It is not usually brave enough to catch adult waterfowl unless these are injured or ill. That’s why when the Marsh Harrier flies overhead, the ducks only have to undertake a short flight to demonstrate they are in good health.


Coot [Fotja, Fulica atra]

Black with white beak, the Coot is unmistakeable. It is quite common in winter and times of migration and less common in spring when occasionally, some pairs stay to breed at Sils. The coot builds a half-floating nest amongst the aquatic vegetation.


Grey Willow [Gatell, Salix atrocinerea]

The grey willow is a small Salix which often grows along the edge of drains. It frequently comes into flower during the month of February, and is one of the first to appear, announcing the arrival of spring. Its bright, white flowers or catkins appear before its leaves and are often used for decoration.


Mallard [Coll-verd, Anas platyrhynchos]

Although the Mallard can be found in Sils all year round, it is in the spring when its presence is more noticeable as a large number concentrate here to breed. It is therefore easy to see the lovely image of a number of cute ducklings swimming behind the female. There are on occasions more than a dozen in the brood.


Northern Shoveller [Cullerot, Anas clypeata]

The Northern Shoveller, when seen close-up, surprises due to its spoon or shovel-shaped bill (from where it gets its name) which allows it to filter its food from the water. The majority of shovellers breed further north, but in the spring during the migration period, they are more common and on some days even abundant in Sils.


Yellow Flag Iris [Lliri groc,Iris pseudacorus]

The yellow flag ris is one of the most characteristic plants of freshwater wetlands. In Sils, they can be found mostly near the drains and channels where their lovely yellow flowers stain the landscape during the months of April and May.



The water level starts to rise again with the autumn rains which favours the stopover of birds migrating south. Little by little the trees lose their leaves and the sedges and reeds dry up. In the middle of winter, the lake awakes on many days, frozen and covered in mist. Birds from the north of Europe, such as Common Snipes, Northern Lapwings, Common Teals and many other small birds settle on the water, the bare trees or in the half-flooded meadows. The flowering of the snowdrop gives a timid note of colour to a cold sleepy landscape.

Common Snipe [Becadell, Charadriiformes]

Coming from the north of Europe, the majority of Common Snipes arrive in the autumn and concentrate in the muddy areas and flooded meadows the whole winter. Its plummage offers perfect camouflage for the environment it lives in and only flies away when it is about to be trodden on. Its zigzagging flight makes it difficult for hunters to hit. For this reason it is often known as the “cartridge-belt emptier”, as it is often necessary to use a lot of ammunition to hit it. As they live on the ground and look for food in the mud, they have developed a wide field of vision, which even allows them to see what is behind them.


Common Reed Bunting [Repicatalons, Emberiza schoeniclus]

In winter many species of small birds visit the lake of Sils from the north of Europe: finches, thrushes, siskins, etc. however one of the most characteristic of flooded areas is the Common Reed Bunting, which can often be seen on the dry stems of the reeds and sedges.


Northern Lapwing [Fredeluga, Vanellus vanellus]

It is well-known that the Northern Lapwing warns of cold weather. Large flocks appear in winter, especially if the temperatures drop considerably, and spread out over open meadow and farmland. On occasions, some individuals remain here in summer and there is the suspicion that some years they have even bred at the lake of Sils.


Snowdrop [Lliri de neu, Galanthus nivalis]

The snowdrop is a delicate and little-known plant that grows in shady and rather cold spots. Its presence in Sils and the rest of the plain of La Selva is attributed, like other similar species, to the humidity and the thermic inversion. It flowers very early (sometimes at the end of January) and its flowers can grow through the snow in places where snow is common. It likes deciduous woodland, especially humid alder and oak woodland. Although many of the original woodlands on the plain have disappeared, its presence usually indicates where alders or oaks would be the dominant species of tree.


Grey Heron [Bernat pescaire, Ardea cinerea]

The Grey Heron is one of the most popular big wetland birds. Its long legs and sharp beak are a perfect combination for catching fish, frogs and crabs. It is a very timid bird which will fly away if it detects a human presence hundreds of metres away. It is also a bit of a bohemian bird as it moves around as it fancies the whole year. Despite being seen all over the place, it only breeds in few places.


Reed [Canyís, Phragmites australis]

The reed grows in waterlogged places or where groundwater is easily reached. In Sils it occupies a large area along the ditches and stands out amongst the sedges. In winter it displays its characteristic dry tufts, full of seeds which are eaten by many small birds. The reed beds are a unique refuge for many birds that live or nest there exclusively and have, in general, become very rare: the Marsh Harrier or the extremely rare Bittern (a strange bird that feeds on eels and at night howls similar to an ox, the origin of many legends) couldn’t live without the presence of extensive reed beds.



Estany de Sils


Humidity: 82%

Wind: 0 km/h

  • 24 Mar 2016 16°C 9°C
  • 25 Mar 2016 15°C 8°C