Cíes Islands

The Cíes Islands need 1 day: walking to the Alto do Príncipe lookout with views of the Vigo estuary, and heading down to Playa de Rodas, named «best beach in the world» by The Guardian in 2007, in the same day. June-September brings the calmest sea for the ferry crossing. They're mid-priced, with access limited to a daily visitor quota. They're part of the Illas Atlánticas de Galicia National Park, and that strict entry cap -reserved in advance- is what preserved Rodas's turquoise water and the low visitor density that sets it apart from other Galician beaches.