July 5, 2026, 5:23 am | Read time: 4 minutes
In the Croatian region of Dalmatia, near the small town of Rogoznica, lies one of the country’s greatest natural wonders. The Dragon’s Eye Lake has long been a mystery, as it seemingly loses its otherworldly blue color without warning. However, there is an astonishing scientific explanation for this. And then there are the numerous legends about the lake’s origin, some even involving extraterrestrials.
Near the small town of Rogoznica in the northern part of Croatia’s Dalmatia region is a body of water of almost otherworldly beauty. On a sunny day, the water of Dragon’s Eye Lake glows in the deepest shades of blue, attracting locals and tourists alike for a relaxing swim. Yet, something strange happens to the lake suddenly and without warning. It loses its color, and all life within it seemingly dies overnight, only to return shortly after as if nothing had happened. There is an astonishing scientific explanation for this phenomenon.
But first things first: Dragon’s Eye Lake covers an area of about 10,000 square meters and has a maximum depth of 15 meters. Up to 24-meter-high steep cliffs surround the body of water, which is only about 100 meters from the Mediterranean Sea and even connected to it underground. This also explains the salt content in the lake’s water. According to the official tourism website of Croatia, a depression formed by the collapse of an underground cave filled with this water during the Ice Age. Another peculiarity is the high content of hydrogen sulfide, a toxic gas. Additionally, there is no oxygen in the lake below a depth of nine meters.
As if the Water Were Boiling
The water in Dragon’s Eye Lake also consists of various layers of different colors. Green and blue on the surface, it can be yellow in the deeper zones and even pink, red, or purple directly above the bottom. This change is caused by the high concentration of hydrogen sulfide. Occasionally, a rare phenomenon can be observed here, as it then appears as if the lake is boiling. This impression is created when the lake loses its color and its water turns milky and cloudy. This occurs due to a mysterious process beneath the surface of Dragon’s Eye Lake.
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The loss of color is due to a chemical process triggered by the sudden mixing of the different water layers. Researchers suspect this could be provoked by earthquakes or seismic activities in general. When this happens, Dragon’s Eye Lake becomes oversaturated with carbon dioxide, hydrogen sulfide, and other gases, making survival impossible. What happens to the aquatic population of the lake in this case remains unclear. Some sources online claim the fauna dies, while according to the official Croatian tourism website, the animals simply migrate to the sea for a while and then return later.
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Legend-Encircled Lake
It’s no wonder that numerous legends surround the unique Dragon’s Eye Lake and its origin. One particularly beautiful story tells of the dragon Murin, son of the goddess Hera and the sea god Poseidon. He supposedly protected the people in the Rogoznica region but demanded a gruesome tribute in return. Every year, the residents had to offer him the most beautiful girl in the village as a sacrifice, whom he then took as his wife. Tragically, none of the brides survived the wedding night, so Murin constantly demanded new appeasements. Until one day, a brave hero appeared.
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This hero arrived on the winged horse Pegasus and fell in love with the girl who was to be offered to Murin. With a miraculous lance forged from moon dust, the hero finally managed to mortally wound the dragon in a duel. As he lay dying, the dragon gouged out both of his eyes. One of them fell at his feet, melted the rock, and thus formed Dragon’s Eye Lake. According to legend, since then, every couple that bathes together in the lake is destined for eternal love with much happiness and many children.
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A second story tells of a pair of brothers who farmed together. When one of them went blind, he asked the other not to disadvantage him during the harvest. However, the wicked brother broke his promise, prompting the wronged brother to summon a dragon with a curse. The dragon is said to have devoured the dishonest brother whole. Another legend attempts to explain the color phenomenon of Dragon’s Eye Lake in a very original way. It claims that a UFO once crashed into the lake. Ever since, whenever the extraterrestrials try to make contact, the water starts to “boil.”