Complexo Ons-O Grove

Complexo Ons-O Grove is one of the most ecologically valuable stretches of the Galician coastline — a Special Conservation Zone (ZEC) that spans the inner waters and coast of the southwestern Ría de Arousa, the Ons archipelago and its surrounding waters, and a section of the northern shore of the Ría de Pontevedra. The protected area stretches across seven municipalities — Bueu, Cambados, A Illa de Arousa, Meaño, O Grove, Ribadumia, and Sanxenxo — covering a combined 7,607 hectares. It's in Sanxenxo, one of the most popular resort towns on the Rías Baixas, that part of this complex lies, making it an easy destination for travelers already based there.

How did this protected area come to be?

The site's protection history goes back to 2004, when the Atlantic Biogeographic Commission of the Natura 2000 network designated Complexo Ons-O Grove a Site of Community Importance (LIC — Lugar de Importancia Comunitaria). That status was a stepping stone: in March 2014 the area was upgraded to full Special Conservation Zone (ZEC) status, bringing stricter legal protection and more rigorous management rules for the habitats and species found here.

What wildlife lives here?

The waters and shores of the complex serve as a refuge for two endangered sea turtle species: the loggerhead turtle (Caretta caretta) and the green turtle (Chelonia mydas), both of which appear here as migratory visitors rather than year-round residents. The area also protects the rare vascular plant Rumex rupestris, typically found clinging to the rocky cliffs of the Atlantic coastline.

Bird colonies are just as significant a draw. The complex hosts spoonbills, easily recognized by their flat, spatula-shaped bills, along with spotted redshanks, curlews, and numerous other wading and water birds that rely on the shallow bays and islands for feeding and rest during migration.

Marine mammals are regular visitors too — porpoises, dolphins, and bottlenose dolphins are commonly seen, especially in the calmer inlets of the Ría de Arousa and around the Ons archipelago.

Why is this area worth visiting?

The combination of islands, shallow bays, cliffs, and river mouths packed into a relatively compact area makes Complexo Ons-O Grove remarkably diverse for its size. For anyone interested in birdwatching, marine wildlife, or simply a quieter encounter with the nature of the Rías Baixas, its proximity is a strong reason to use Sanxenxo as a base. Keep in mind that, as a ZEC, the zone is subject to specific conservation rules — some activities, such as boating or access to particular zones, may be regulated or seasonally restricted.

Frequently asked questions

What's the difference between a ZEC and an ordinary nature park? A Zona Especial de Conservación is a formal designation under the EU's Natura 2000 network, granted to areas of particular importance for preserving habitats and species listed in the Habitats Directive. It carries specific monitoring and protection obligations that go beyond the earlier, provisional LIC status.

Which municipalities does the protected area cover? Complexo Ons-O Grove spans seven municipalities: Bueu, Cambados, A Illa de Arousa, Meaño, O Grove, Ribadumia, and Sanxenxo.

Can you see sea turtles in this area? Yes, though as migratory species their presence isn't guaranteed year-round — both loggerhead and green turtles appear seasonally in the complex's waters.

How large is the protected area? The complex covers a total of 7,607 hectares, including marine waters, sections of coastline, and the Ons archipelago itself.