Travel warning: Several beaches in Spain closed after rare ‘Blue Dragons’ appear on shore; 5 beaches to avoid

In a recent turn of events, popular beaches in Spain have been closed to visitors after venomous blue dragon sea slug (Glaucus atlanticus) were spotted on shores. It was an unsettling sight that scared the people. These beaches, which are usually sun-soaked and tourist-friendly, have turned deadly with the sudden appearance along parts of the Costa Blanca.

Authorities have been forced to raise red flags and temporarily shut down beaches. Mayor José Luis Sáez said: “Do not touch them, not even with gloves. If stung, rinse with salt water and head straight to a health center.”

Marine experts believe that shifting ocean currents and rising sea temperatures, possibly linked to climate change, may be responsible for these unusual appearances of the blue dragons.

What happened?

The first time these deadly sea creatures were spotted was around August 20, 2025, on Guardamar beaches. Then Playa Ortigues, La Mata (Torrevieja), and Vivers Beach also reported the presence of blue dragons. Soon the town council closed all the bathing regions.

Don’t mistake blue dragons for mythical beings. These tiny, venomous sea slugs, only 3–4 cm long, are both stunning and dangerous. With their striking blue bodies and silvery undersides, they seem almost otherworldly. But contact with humans can cause intense pain, skin burns, nausea, or vomiting, often requiring urgent medical care.

On this note, let’s have a look at five beaches in Spain where blue dragons (Glaucus atlanticus) were recently spotted and swimming was temporarily banned in August 2025:

Playa Centro is among the most prominent family-friendly beaches on the Costa Blanca. It was the first beach that was shut to visitors soon after blue dragons were spotted. Authorities have raised red flags.

Playa Ortigues is another beautiful, visitor-friendly beach with reported blue dragons. This quieter beach is also shut and patrol teams are stationed along the shore. No visitors allowed here.

Vivers Beach is noted for its long sandy stretch. It was also closed after several blue dragon specimens were spotted on shore. Officials reminded tourists that even dead or stranded blue dragons are dangerous to touch.

Just a few kilometers south of Guardamar, La Mata also reported sightings of blue dragons. The incident has left locals and travellers worried because this beach is a hotspot for both party lovers.

Some beaches in Mallorca have also spotted blue dragons. It was quite shocking because blue dragons were spotted here after almost 300 years! The incident has been connected to unusual sea currents and climate change, making it a rare natural spectacle.