Reserva Marina de les Illes Columbretes

Reserva Marina de les Illes Columbretes is a protected marine area surrounding a small archipelago of volcanic islets in the Mediterranean Sea, roughly 30 nautical miles off the coast of Castellón, about halfway between the Balearic Islands and the Valencian mainland. The reserve covers close to 5,500 hectares of sea, while the emerged land totals only 19 hectares — 14 of which belong to the largest island, known as Illa Grossa or Columbrete Grande.

How did the islands form?

The Columbretes islands were formed during the Pleistocene, nearly a million years ago, through a series of underwater volcanic eruptions. The archipelago is made up of four groups of volcanic islets rising from a seabed that reaches depths of 80 metres. This rugged, barren landscape has long unsettled sailors, and the islands' name has been associated for centuries with a treacherous stretch of sea.

What is the history behind the archipelago?

For centuries the islands served as a hideout for smugglers and pirates, as well as a seasonal fishing base used until the early 19th century. During the 19th century the islets were deliberately burned to reduce reptile populations, and in 1856 a lighthouse was built there, marking the start of permanent settlement by the keepers who maintained it. Smuggling activity, on a smaller scale, continued into the 20th century.

When and how were the islands protected?

Formal protection began in 1988, when a decree by the Valencian regional government established a natural park covering the archipelago. Two years later, on 19 April 1990, a ministerial order created a marine reserve of 4,400 hectares around the islands. In 1994, protection was strengthened further when a law passed by the Valencian parliament reclassified the archipelago as a nature reserve, placing it under the highest level of environmental protection available in the region.

What wildlife lives on the Columbretes?

The archipelago is an important nesting site for seabirds, including Eleonora's falcon, the Audouin's gull, Cory's shearwater and the shag. Because of its position along the migratory route between Europe and Africa, the islands also serve as a key stopover point for migrating birds. On land, an endemic subspecies of the Iberian wall lizard — known as the Columbretes lizard — lives alongside at least ten endemic insect species. Underwater, visitors would find beds of kelp-like brown algae, colonies of red coral, and large populations of fish such as groupers, gilt-head bream and white seabream. The surrounding waters are also an important breeding ground for spiny lobster.

Can you visit the Columbretes?

Due to the fragility of the natural environment, visits are strictly limited. Only the largest island, Illa Grossa, can be visited, and only in small groups accompanied at all times by the reserve's rangers. The rest of the archipelago remains off-limits to visitors, which helps protect the nesting colonies and unique habitats found there.

Frequently asked questions

How far are the Columbretes from the mainland? The archipelago lies about 30 nautical miles off the coast of Castellón, roughly halfway between the Balearic Islands and the mainland.

How old are the islands? They were formed during the Pleistocene, through volcanic eruptions that occurred nearly a million years ago.

Can you visit the islands independently? No — access to Illa Grossa is only possible in small, organised groups accompanied by the reserve's rangers.

Which birds nest on the Columbretes? Species such as Eleonora's falcon, the Audouin's gull, Cory's shearwater and the shag nest on the islands.