05 October 2026
(The Kuyalnik Estuary in winter. PHOTO: Dmytro Zhdanov)
Today we’ll take a walk through the grounds of the newly established national nature park. We’ve already written about the historical landmarks of Kuyalnik, but the Kuyalnik Estuary is, above all, a unique natural site. The summer heat has passed, so it’s the perfect time to set out on a day-long expedition to discover the natural wonders of this region.
Just a few kilometers from the “Kuyalnik” health resort, we notice that the estuary’s steep banks hold evidence of ancient eras—fossilized remains of animals that inhabited this area millions of years ago. Numerous fossilized remains of prehistoric camels, mastodons, and hipparions have been discovered along the shores of Kuyalnik. Sometimes rain washes the bones of these ancient animals out of the rock formations exposed on the slopes of the Kuyalnik ravine, and then they can be found right on the ground.
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Ahipparion tooth. PHOTO: Dmytro Zhdanov
Numerous paleontological finds along the coast of the Kuyalnik Estuary indicate the advisability of establishing a paleontological reserve here.
The cliffs bordering the Kuyalnik ravine are also very picturesque. Here, one finds clays, loams, limestones, and marls, which give the slopes a mottled appearance. Periodically, the rocks begin to shift, and the landscape changes in an instant—such are the consequences of landslides.
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The landscape after landslides. PHOTO: Dmytro Zhdanov
And among the fallen rocks, you can find interesting “gypsum roses.”
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“Gypsum roses.” PHOTO: Dmytro Zhdanov
The formation of the estuary’s shores was also influenced by the so-called “Kuyalnik Fault.” It formed millions of years ago and remains active to this day. Interestingly, on both sides of the fault, the Kuyalnik shore rises and subsides at different rates.
The deep Kuyalnik Fault has other consequences as well, which were documented over a hundred years ago. These are radioactive emanations. In particular, the newspaper “Odessa Listok” published another article on November 17, 1913, about radioactive emanations in the Kuyalnik Estuary. The impetus for this was an appeal by V. A. Bertenson, a member of the city council, to the mayor proposing to begin searching for radium deposits in the Odessa estuaries. Of course, there are no radium deposits in the estuary, but instruments periodically detect radioactive emanations. I recorded readings of up to 40 microroentgens, which does not exceed the health standard of 50 microroentgens but is 2–3 times higher than the normal background radiation level in the estuary.
Among the interesting geological formations in Kuyalnik are small caves in loamy rocks. They may form as a result of suffosion: water seeping through the rock gradually carries away fine clay and sand particles, widening cracks and underground channels. On the plateau above such cavities, sinkholes sometimes form, into which water flows during rains. As the water penetrates deeper into the rock, it continues to erode it, and over time, the underground channel may emerge onto the surface of the slope, forming the entrance to a small cave.
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Suffosion cave. PHOTO: Dmytro Zhdanov
In 1938, an expedition led by Tymofii Hrytsai discovered a unique cave near the village of Illinka in Mizhlymannia. The partially collapsed cave was located on the northern outskirts of the village, on the right slope of a ravine that flows into the Kuyalnik Estuary. During the excavations, tens of thousands of mammal bones were discovered, including those of bison, hyenas, wolves, and rhinoceroses. The largest number of bones belonged to cave bears. Of course, this cave no longer exists today (it was destroyed by natural processes many years ago). However, flint tools dating back thousands of years are still found in the estuary today.
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Aflint arrowhead. PHOTO: Dmytro Zhdanov
Everything about the Kuyalnik Estuary is unique. Even the ordinary sand on the estuary’s shore can sparkle like treasure when viewed under a microscope.
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Sand from the Kuyalnik Estuary under a microscope. PHOTO: Dmytro Zhdanov
During dry years in August and September, before the rainy season begins, the estuary’s bottom is covered with a layer of naturally deposited salt. We’ve already written about the history of the Kuyalnik salt industry. Incidentally, under current conditions, this salt could be harvested and sold as a branded product called “Kuyalnik Salt.” This would help the estuary get rid of excess salt and could generate significant revenue.
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Naturally deposited salt in the Kuyalnik Estuary. PHOTO: Dmytro Zhdanov
Salt crystallization in the Kuyalnik Estuary begins when, as a result of evaporation, the brine becomes saturated or supersaturated with salts. Numerous crystals then form within it; these gradually grow and often take on whimsical shapes, resembling true works of art.
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A “work of art” made of naturally formed salt. PHOTO: Dmytro Zhdanov
Let’s conclude our story with another valuable natural resource of Kuyalnik— the mineral waters that have been extracted here for many years. We’re talking about the “Kuyalnik” mineral water deposit.
Several mineral water deposits, primarily sodium chloride deposits, are known within Odessa and its surroundings. Among the largest are the Odessa and Kuyalnik deposits.
The Odessa deposit is located on the grounds of the sanatorium at 165 Fontanska Road. Two wells, 150 and 210 meters deep, are used to extract the mineral water.
Within the Kuyalnik deposit, two main types of mineral water are utilized. The first type consists of sodium chloride waters from the Upper Sarmatian aquifer with low mineralization. It is extracted from wells and used, in particular, for bottling “Kuyalnik” mineral water and supplying the resort’s drinking fountain. This water is used for therapeutic and dietary purposes to treat certain digestive disorders.
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Drinking fountain with artesian water. PHOTO: Dmytro Zhdanov
The second type consists of highly mineralized sodium chloride waters from the Upper Eocene aquifer. These are used primarily for external balneological treatments, particularly in the treatment of diseases of the nervous and cardiovascular systems. A mineral spring on the grounds of the Kuyalnik resort is mentioned, in particular, in the 1934 guidebook “Odessa Resorts.”
The first wells on the estuary were drilled as early as 1895, and in 1914–1915, special drinking fountains were installed here. The drinking fountain, which is now located next to the treatment building, was built in the 1950s.
If you’ve already made it to the estuary, I recommend finding this interesting and picturesque spring. That said, not everyone will be able to find it. The estuary keeps its secrets well. The only landmark along the way is the “Avgustivka” bus stop; from there, you’ll need to walk about two kilometers toward the estuary. On your right, you’ll see a ravine overgrown with vegetation—that’s where the spring is located. And while it may be hard to spot, it’s much easier to hear. By following the sound, you’ll find a small path leading down into the ravine.
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Filatov’s Spring. PHOTO: Dmytro Zhdanov
According to local legend, Filatov used to bring some of his patients to this spring, believing the water to be healing. And supposedly, the patients’ condition improved. However, no written evidence of this story has been found, so it is most likely just one of the legends of Mizhlymannia. Perhaps it arose because of the water’s unusual taste, which sets this spring apart from other local ones.
Filatov’s Spring is a wonderful reminder that the Odessa region hides not only salt and catacombs but also genuine natural treasures, sanctified by science and legends. It’s a must-see destination for anyone seeking the true, off-the-beaten-path gems of southern Ukraine.
We have received a legacy from nature—a balneological gem of Europe, the unique Kuyalnik Estuary. But will we be able to preserve it for future generations?
Дмитро Жданов
Oct. 5, 2026
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