Plato, an ancient Greek philosopher of classical-era Athens, said in his works Timaeus and Critias that a powerful naval empire called Atlantis had existed on a large island in the Atlantic Ocean. It supposedly conquered most of Europe and northern Africa but ultimately was swallowed by waters.

Although Atlantis is widely believed to be a fictional entity, it has fueled the imagination of many explorers and treasure hunters for centuries. The search continues to this day.

Recently, a bold new claim stirred debate in both archaeological circles, historians’ communities, and the public imagination.

Michael Donnellan, an archaeologist and filmmaker, believes that he may have discovered its ruins just two miles off the coast of Cádiz, Spain.

Based on eight years of research, sonar scans, and more than 20 underwater dives, Donnellan says the submerged site matches Plato’s ancient descriptions “verbatim” and could be the remnants of a sophisticated prehistoric civilization wiped out by a cataclysm 11,600 years ago.

“It matches everything Plato says verbatim,” Donnellan told journalists. “We know that perfectly well to this day that Gades is the modern-day Cádiz.”

At a presentation during the Cosmic Summit in North Carolina, Donnellan revealed stunning sonar and LiDAR images that show enormous concentric circular walls — some over 20 feet tall — on the seafloor near Cádiz, a city known as the oldest in Western Europe.

The location where the ruins were found. Credit: NewsCafe via Google

The layout, Donnellan argues, aligns exactly with the ancient city of Atlantis as described in Plato’s Timaeus and Critias. At the heart of these rings lies a rectangular structure-oriented north-south, which he believes is the Temple of Poseidon.

“The layout matches perfectly with Plato’s descriptions,” he said in another interview, noting sharp right angles, cut stone blocks, and a canal system. His team recorded countless artifacts, including enormous rectangular stones roughly the size of half a small car, stacked and scattered in patterns inconsistent with natural formation.

All these are “hard evidence” that Atlantis has finally been uncovered, the researcher said while teasing the public about his new movie on the topic.

“Upon observation, clearly cut stones are seen stacked one on top of the other,” Donnellan noted. “The style of construction, however, is certainly not Roman nor Venetian. And at this distance and depth, it would make this place much, much older.”

Donnellan suggests the damage visible on the outer rings — fractures, collapsed walls, and stones thrown from original positions — could be the result of a massive tsunami, aligning with Plato’s account of Atlantis vanishing “in a day and a night of earthquakes and floods.” He links the destruction to the Younger Dryas, a sudden climate event that occurred around 11,600 BC, the same time Plato gives for Atlantis’ demise.

The site’s location — beyond the ancient “Pillars of Hercules” (now known as the Strait of Gibraltar) — further supports the theory, as Atlantis was said to lie in the Atlantic Ocean, west of the Greek world.

Michael Donnellan had been searching for Atlantis for eight years. Credit: Ingeniofilms

The measured size of the region, the explorer goes on, again aligns with Plato’s description of Atlantis spanning 3,000 by 2,000 stadia, or approximately the size of Nevada.

While many historians still regard Atlantis as a philosophical allegory, Donnellan hopes his findings will open the door to wider acceptance of its possible reality. He proposes thinking of the site as part of a “great ancient Atlantic culture.”

“Perhaps we should now speak of an ancient Atlantic culture. It’s easier to believe when the evidence speaks for itself,” he stated. “I think that’s a gateway to letting people slowly, over time, take the word Atlantis much more seriously.”

The full details of the discovery are set to be revealed in a documentary by his company Ingeniofilms, featuring the underwater expeditions. The premiere took place last October at the South International Series Festival in Cadiz and at the Malaga Film Festival.

Past findings of Atlantis

Whether true or not, one important detail that contradicts Donnellan’s claims is that the Temple of Poseidon is part of the Ancient Greece culture, which appeared much later, rather than an Atlantis attribute. After all, Atlantis has left no written record about itself.

This fact makes scientific consensus impossible, though it has undoubtedly reignited global fascination with one of history’s most enduring mysteries. The ruins Donnellan discovered are old indeed and may belong to an older version of Gades, which has sunk due to climate changes and continental shifts.

This is not the first time someone claims to have discovered the lost ancient civilization of Atlantis.

Atlantis presented as a city. Credit: Ingeniofilms

Before Donnellan’s recent claims near Cádiz, a team of researchers led by German physicist Rainer Kuhne and archaeologist Richard Freund pointed to the marshlands of the Doñana National Park, also in southern Spain. Using a combination of satellite photos and ground-penetrating radar, they identified strange geometric shapes and buried structures, such as fireplaces and canals, which they argued were consistent with a city destroyed by a tsunami.

American researcher Robert Sarmast has been one of the most persistent searchers for Atlantis in the eastern Mediterranean. In 2004, he claimed to have found “irrefutable” evidence of man-made structures on a submerged hill 80 kilometers off the coast of Cyprus. Using deep-water sonar scans, his team identified what they interpreted as a 3-kilometer-long wall, a walled hill summit, and deep trenches on the Latakia Ridge between Cyprus and Syria.

One of the most famous alleged Atlantis sites is the Bimini Road, a half-mile-long underwater formation off the coast of North Bimini in the Bahamas. Discovered in 1968, it consists of large, rectangular limestone blocks arranged in a J-shaped pattern, which some believe are paving stones or a wall from the lost civilization.

However, the scientific consensus is that the Bimini Road is a natural geological feature formed by beachrock, a type of sedimentary rock that can crack and settle into tile-like patterns.

Others argued that Plato’s geography was misunderstood or that his measurements were in different units. Author Jim Allen proposed that Atlantis was not a sunken island in the ocean, but a sunken plain high in the Andes Mountains of Bolivia. He identified the Altiplano, a large highland plateau near Lake Poopó, as the site.

A piece of alleged Atlantis ruins, according to a new theory by Donnellan. Credit: Ingeniofilms

Perhaps the most dramatic theory is that Atlantis is not at the bottom of the ocean, but buried under miles of ice in Antarctica. Authors Rand and Rose Flem-Ath argue that around 12,000 years ago, the Earth’s crust shifted in a cataclysmic event known as earth-crust displacement.

This theory, once considered by Albert Einstein, suggests that land which was once temperate was suddenly dragged into the polar zone and frozen. The Flem-Aths cite ancient maps, such as the Piri Reis Map of 1513, which they believe accurately depicts the coastline of Antarctica without ice, as evidence for this advanced, prehistoric civilization.

Well, Donnellan is surely not the first who “found” Atlantis — and probably he won’t be the last one.