The mystery of glowing waters
Imagine a pitch-black summer night on the Atlantic coast of Spain. You stand at the water’s edge, and as the wave rolls in, it suddenly bursts into a myriad of neon-blue sparks, as if someone scattered a handful of liquid stars over the ocean. This is neither fiction nor an optical illusion. It’s the ‘mar de Ardora’, or ‘burning sea’—one of nature’s most spectacular displays. For centuries, Galician fishermen have passed down legends about this phenomenon, seeing it sometimes as an omen, sometimes as a sign of magic. This very spectacle, perched on the edge of myth and reality, so captivated Jules Verne’s imagination that he immortalized it in his famous novel, Twenty Thousand Leagues Under the Sea, offering readers around the world a glimpse into the mystery of luminous depths.
The science behind the magic
What once seemed like a miracle to our ancestors is now explained by science and known as bioluminescence. The fantastic glow is produced by billions of single-celled organisms, mainly dinoflagellates of the species Noctiluca scintillans, which translates as ‘shimmering night light.’ These microscopic creatures, drifting in the water column, can produce light through a chemical reaction. Their cells contain the pigment luciferin and the enzyme luciferase. Any mechanical disturbance—whether it’s a wave crashing on rocks, the movement of an oar, a hand stirring the water, or simply a passing school of fish—triggers an oxidation process, releasing energy in the form of a cool blue glow. For the plankton, this is primarily a defense mechanism, a sort of ‘alarm system’ that disorients and deters predators. For us, it becomes a mesmerizing light show created by nature itself.
Where else in the world does the sea glow
Although Galicia is justifiably considered the Spanish epicenter of this phenomenon, it is not the only place on the planet where you can witness such a marvel. There are more than two hundred locations where the nighttime waters light up with living fire. Among the most famous are Mosquito Bay on the island of Vieques in Puerto Rico, where the concentration of dinoflagellates is so high that the glow is visible almost every night. Also well-known are Springbrook National Park in Australia, Ha Long Bay in Vietnam, and Toyama Bay in Japan. A unique site is the Waitomo caves in New Zealand, where the ceilings are illuminated not by marine organisms, but by thousands of fungus gnat larvae. Each of these places demonstrates nature’s diversity and ingenuity. However, the chance to see this rare phenomenon on the European continent, particularly on the coast of Spain, makes it especially valuable for travelers.
A guide to Galicia’s glowing beaches
Why Galicia? A unique set of factors makes this region the perfect stage for a nighttime spectacle. The clean, nutrient-rich waters of the Atlantic, a rugged coastline dotted with secluded coves, and relatively warm summers for these latitudes create ideal conditions for a phytoplankton bloom. The best time to ‘hunt’ for the ‘mar de Ardora’ is from July to late September. Key ingredients for success: warm water, a moonless or crescent moon night, and a spot far from city light pollution. Patience is your main ally here. Among dozens of potential spots on the map, a few stand out as the most reliable: the vast Carnota Beach, the cozy Balarés Beach in Ponteceso, the Costa da Morte coast near Malpica and Muxía, and the idyllic Figueiras Beach on the Cíes Islands. But in truth, the magic can appear on any wild beach from A Coruña to Pontevedra. This is an adventure with an unpredictable ending, with a reward as vivid as the wildest fantasies from a novel.
