One of the most unique areas of O Grove is its isthmus. Thanks to him, the municipality is formed as a peninsula, serving as the only access route to the destination. It is also an environment of undoubted both landscape and ecological interest, since it is framed within the limits of two important protected areas: the Umia-O Grove Intertidal Complex and the Ons-O Grove Intertidal Complex. Or Grove.

Its western margin is entirely occupied by the largest sandy area in the province of Pontevedra: A Lanzada beach. Bathed by the waters of the Atlantic Ocean, numerous surfers come throughout the year to ride its waves. From here you can see the island of Ons, belonging to the Atlantic Islands National Park, and magical sunsets.

The isthmus itself is made up of a huge dune complex. Protected birds such as the snowy plover nest here. A wooden walk crosses the dunes with special care not to damage the environment.

Finally, the eastern margin of the isthmus is bathed by the waters of the Arousa estuary. In this important intertidal zone, several bird observatories are installed from which to spot a wide variety of migratory birds.