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The Eo Estuary
Castropol y Vegadeo (Western Asturias)
Open to the public

Summer and winter (the time of year with the greatest influx of waterfowl)

14 km2
Contact Address

Castropol Visitor Reception Centre.
La Fuente, 15.
33760 Castropol.

Phone 985 710 013

Plaza del Ayuntamiento, S/N.
33770 Vegadeo.

Phone 664 476 415

Eo Estuary Interpretation Centre.
Old Serrasa Factory.
33760 Castropol.

Phone 985 635 001

  • The Eo Estuary Partial Nature Reserve is located in the northwestern corner of Asturias, between the boroughs of Castropol and Vegadeo.

  • Plant life

    In terms of vegetation, perhaps the most original species are the seagrass meadows formed by the two species of eelgrass: Zostera marina, mainly found in Linera Cove in what is probably the most extensive formation in the Bay of Biscay, and Zostera noltii, which is found in this and other inlets.

    Some halophilic thickets also grow here, while some rushes and reeds can also be found in those areas less affected by high tides.


    The Eo Estuary is considered the main wintering and resting area in Asturias for European migratory waterfowl populations and has plant communities which are unique to these coastal landscapes.

    49 species of birds have been identified, of which 16 are waders, 13 are ducks and 9 are gulls, the remainder being distributed among other groups. The majority winter here, although there is a small group that migrate in spring and autumn and one group that can be seen throughout the year.

    This wetland is classified as being of international importance in regard to three species of ducks: the wigeon, pintail and tufted duck. The presence of important populations of oystercatcher, grey plover, dunlin, common sandpiper, whimbrel and bar-tailed godwit have led to the wetland being classified as an area of regional importance for these species.

The Eo Estuary Partial Nature Reserve is one of the best preserved estuaries in the region, whose primary interest lies in its birdlife and vegetation.

The eastern boundary of the reserve is situated at Espiela Point, where it continues along country lanes and local roads to Figueras. From there, you follow the road which joins up with the N-640. Continue along the N-640 southward, passing through Castropol and Vegadeo. At this point take the road which passes through Miou before reaching Louteiro. The road continues straight on from there, linking Louteiro to the Galician village of Villafernando (Trabada).

The point of intersection with the regional boundary constitutes the southern end of the area. The western boundary coincides with the provincial border until reaching the mouth of the estuary at La Cruz Point, where the reserve ends.

The shape of the estuary is dominated by a longitudinal fault and a series of minor faults forming inlets. The estuary is divided into three zones, one where the waters are completely mixed at its mouth, turning into a partial mix towards the middle and ending in a fully saline area at the tail end of the estuary. The ground consists mainly of slate, sandstone and quartzite, with limestone and dolomite appearing in the vicinity of the estuary.

This navigable estuary provides lovers of water activities an unforgettable experience, rowing and sailing being the most common, thanks to the estuary's breadth and fishing tradition. You can take a boat ride on the estuary from the small coastal jetties in Castropol, Figueras and Ribadeo. Top class oysters are also being farmed here.

The Eo Estuary
GPS: 43.525155,-7.030433