Gaze west from one of the crows-nest hilltops on Monteagudo (“Sharp Mount”) island, and you can just about imagine the rooftops of Atlantis beneath the Atlantic swell. One of the three islands that comprise the Islas Cíes archipelago, about nine miles off the Galician coast, it is where Captain Nemo, hero of Jules Verne’s 1871 novel Twenty-Thousand Leagues Under the Sea, salvaged the treasure that funded his adventures. Verne’s choice of location makes sense.

Everything about this collection of islands carries a hint of myth and magic, from its coastal caves and high cliffs to its secret coves and squally seas. It was designated a nature reserve in 1980 and later a maritime park, and humans play a distant second fiddle to the permanent residents, which include such delights as the sea-pink “love plant” ( ) and an underwater algae forest a stone’s throw from the shore. On the Islas Cíes, visitor numbers are capped, so there’s no scrum for space on the beach or long queues at the handful of eateries For all their Treasure Island-like wilderness (the other islands, south of Monteagudo, are Isla del Faro and uninhabited San Martiño), the big lure of the Islas Cíes is how close their crystalline waters and pale sandy beaches are to the mainland.

In less than an hour by boat from Vigo (about €23pp), you can be sunbathing on Praia de Rodas, a Colgate-white strip of fine sand that links the two northern islands and can compete with any in the Caribbean. Chil.